Download Muscular Analysis of the Power Snatch Lift

Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Muscular Analysis of the Power Snatch Lift
HPSS 3130-01 Kinesiology
Tennessee State University
Matthew Nuessle
April 17, 2015
1 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Introduction
This paper is focused on the muscular analysis of a complex weightlifting movement
known as the power snatch lift. The power snatch is a movement that involves “rapidly lifting a
barbell from its starting position on the floor to an overhead position in one continuous motion”
(Newton, 2002). According to Newton, the snatch lift has three different variations. These
variations include the following: the squat snatch, split snatch, and the power snatch. This
analysis will focus specifically on the power snatch phases; the muscles involved in each phase;
the actions these muscles are performing; the importance of proper biomechanics during these
phases; proper training techniques, and the intended results along with how to measure results
through testing.
This activity was chosen for the purpose of improving the execution of the power snatch
through the SEE Principle; which described in our text as performing with optimum safety,
effectiveness, and efficiency (Hamilton, 2012). The results of this analysis will provide a better
understanding of the power snatch to anyone who has the desire to properly and safely execute
this lift.
2 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Chapter I
There are numerous opinions as to when the actual power snatch begins. The variations
found differentiate between five and seven phases. For a more in depth analysis, seven phases of
the lift will be described in detail for the power snatch. These phases are known as the starting
position, liftoff, scoop, jump phase, pull-under, catch, and recovery.
The barbell path will not be in a straight line from start to finish. It will exemplify what
is known as an elongated S, known as an “S-pull” (Newton, 2002). Although this style of pull
was once seen as a violation, it has been proven to be a much more effective way to move a
considerable amount of weight from the floor to overhead.
Starting Position
3 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT The first phase of the power snatch is known as the starting position. This is where the
lifter positions their body with the proper form so that they are able to make a safe and effective
lift. The starting position is also considered the pre-lift phase (Huwang, Lee, Tsuang, 1995).
Newton goes into detail as to how the lifter should position their bodies to prepare for this lift.
He first describes this set up as having the feet around hip-width apart with the feet flat on the
ground. Notice in the image above where the bar is positioned in relation to the foot. According
to Newton, it is proper technique to position the bar over the first metatarsal-phalangeal joints of
the feet. This will cause the lifter to focus the body weight towards the front of the foot. While
keeping the back straight; the lifter should lower their body to the bar by bending the hips
(anterior tilt), knees (flexion), and ankles (dorsiflexion). The hips should be even or slightly
higher than the knees; forcing the shoulders to be positioned just over, or slightly in front of the
barbell. The knees should be driven laterally for more stability while keeping the feet facing
forward. Shoulder blades should be retracted at this point; helping to keep the back straight.
Elbows should also be rotated outward so that they are over the bar. Chest should be up with the
head in a neutral position with the eyes focusing straight ahead (Newton, 2002).
How is this position effective in relation to the Law of Motion? Newton’s first law of
motion states that “a body continues in its state of rest or of uniform motion unless an
unbalanced force acts on it” (Hamilton, Luttgens, Weimar, 2012). The law of motion that
applies to this phase is the Law of Inertia. This is defined by Hamilton as when an object is at
rest it will stay at rest until something causes it to be set in motion. The barbell is currently at
rest during this time. The law of reaction plays a role in this phase as well. It is said that in
reference to the law of reaction, for every action, there is an equal and opposite reaction
(Hamilton, Luttgens, Weimar, 2012). The weight is exerting a level of force on the platform,
4 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT which is keeping it stable by exerting an equal amount of resistance; therefore keeping the
weight from falling through the floor. The lifter positions their selves strategically to be able to
lift the bar in a way that causes as little interference with the line of motion as possible. “In
order to use power and speed in the pulling phase as efficiently and effectively as possible, the
role of the neuromuscular system in the pre lifting phase has had to be properly interrelated and
matched with the task demands” (Huwang, Lee, Tsuang, 1995).
Determining the proper grip width is a crucial step to learning how to execute the snatch
efficiently. To determine the width of your hands make sure that during the catch phase, “the bar
is held at arms’ length about four to eight inches above the head” (Newton, 2002).
The most popular grip for complex pulling lifts such as this is the hook grip; which is
only used for pulling exercises. As shown in the image above; the hook grip is accomplished by
overlapping the thumb with the middle and index fingers followed by the remaining digits. This
is known to add up to 10% of lifting potential (Newton, 2002).
5 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Liftoff
The liftoff phase is where the barbell is put into motion by the lifter. This phase is also
known as the first pull. This phase involves the lifter extending his hips and knees. At this point
the bar will move slightly in towards the shin causing the lifter’s balance to shift from the front
of the foot to the mid foot. The torso’s angle should not change as the barbell arrives at knee
level (Newton, 2002).
The laws of motion applied to this phase are the law of inertia, the law of acceleration,
and the law of reaction. The law of acceleration is put into action when the lifter exerts enough
force to begin moving the barbell off of the ground. The lifter’s capabilities as well as the
weight of the barbell are factors resulting in the initial speed of the barbell during the lift. This
law is defined as “the acceleration of an object is directly proportional to the force causing it, is
in the same direction as the force, and is inversely proportional to the mass of the object’
(Hamilton, Luttgens, Weimar, 2012). The law of reaction is “that for every action, there is an
equal and opposite reaction” (Hamilton, Luttgens, Weimar, 2012). The action put towards
moving the weight off of the ground and to the knees is the result of the lifter exerting the
necessary force to cause that reaction. The law of inertia is being put into action as the lifter
6 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT creates momentum by creating enough force to move the weight from the ground toward the
knees.
Scoop
This scoop phase got its name because you are basically scooping your legs under the bar
as you transition from the first pull to the second pull. This is also known as the transition phase
(Newton, 2002). Refer to the image above and notice how the lifter starts with the bar slightly
above her knees (blue). The yellow figure demonstrates her beginning to raise her shoulders
vertically by extending her hips causing the bar to pass over her thighs. Notice the increased
degree of dorsiflexion in the ankles and flexion in the knees, and hips between the blue and
yellow figures. You can also notice how the weight is shifted from her mid foot to the balls of
her feet (yellow). “The bar passes in front of your thighs until it reaches about mid-thigh, at
which point you bring your hips to the bar” (Newton, 2002). The end of the transition phase is
demonstrated by the green figure, where the bar is now in contact with the top of her thighs.
It is important to notice how the bar path is mostly straight up between the blue and
yellow image. Notice how the edge of the black weight plate on the barbell is in line with the
heel in blue, and it has only slightly moved forward for the yellow figure. This is important to
7 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT keep in mind when referring to the laws of motion. The law of inertia is taken into consideration
by the lifter by scooping her thighs under the bar, instead of severely interrupting the original bar
path. This next phase is called the jump phase, or the second pull (Hamilton, Luttgens, Weimar,
2012).
Jump Phase
The scoop phase allows the lifter to transition from the 1st pull to the 2nd pull by
positioning the lifter into what is known as the “power position” where the bar contacts the upper
thigh while the shoulders are kept over the bar as long as possible (Newton, 2002). This is the
most powerful movement of the lift because the objective is to propel a significant amount of
weight in one movement so that the lifter can pull their body underneath to complete the snatch.
The movement is basically a vertical jump that propels the weight by plantar flexion of the
ankles; and extension of the knees, and hips simultaneously, according to Newton. “At the end
8 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT of this movement, strongly contract the trapezius muscles of your upper back and begin to
quickly bend your elbows, which remain over the barbell” (Newton, 2002).
All three laws of motion are in place for this phase. The law of reaction is put into place
when the lifter executes the jump which causes the bar to rapidly propel upwards. This rapid
movement compliments the law of acceleration because, during this phase the bar is brought to
its fastest speed during the lift (Hamilton, Luttgens, Weimar, 2012). During a barbell
acceleration experiment, researchers found that “peak barbell acceleration stayed relatively
constant from 50% to 80% of 1RM” (Sands, Sato, Stone, 2012). Another study showed that the
vertical velocity of the barbell during the second pull can range between 1.65 m/sec and 2.28
m/sec; propelling the bar just over 5 mph (Smith, Storey, 2012). The law of inertia is being
represented by the upward momentum of the barbell traveling uninterrupted (with exception to
gravity) to the pull under position (Hamilton, Luttgens, Weimar, 2012).
9 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Pull-Under
The pull-under (also known as the turnover) is exactly what it sounds like. The lifter is
pulling their body under the barbell while its momentum is still carrying it upward (Newton
2002). According to Newton, this phase is necessary for lifters because of the fact that the arms
are the weakest contributors to the lift. To make sure the barbell goes overhead, you are to
actively pull body weight under the bar. “This maneuver, which is actually very difficult to
accomplish, can only be performed with your feet on the floor” (Newton, 2002). Notice in the
picture, the lifter’s wrists are flexed; her feet are flat on the ground; and she is actively lowering
herself under the bar.
10 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT The 3 laws of motion are applied to this phase as well. The law of inertia is put into
effect as gravity prevents it from rising any higher. The law of reaction is apparent when the
lifter uses the barbell to pull their body under the bar to transition into the catch phase. The law
of acceleration is put into place as the lifter accelerates their body weight under the bar
(Hamilton, Luttgens, Weimar, 2012).
Catch
The catch requires the lifter to quickly rotate their elbows forward and push up against
the barbell, which is losing its upward momentum (Newton, 2002). Notice how the wrists are
extended backwards and the wrist, arm, and shoulder are aligned as the barbell is being held
overhead. There is flexion in the ankles, knees, and hips as a result of the pull under.
The laws of motion seen for this movement are the law of inertia and the law of reaction.
Inertia is displayed by the lifter’s ability to stop the weights intended downward motion. The
11 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT law of reaction is seen as the weight of the bar naturally wants to drop to the ground, but the
lifter has positioned their bodies to keep the bar in place (Hamilton, Luttgens, Weimar, 2012).
Recovery
Recovery occurs when the lifter extends his ankles, knees, and hips into a standing
position. When the lifter has accomplished this, like in the image above; they have completed
the lift. The law of inertia is represented as the weight is stabilized above the head. The law of
reaction is displayed as the weight of the barbell and the strength of the lifter combined keep the
weight from moving downward (Hamilton, Luttgens, Weimar, 2012).
12 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Chapter II
There are a considerable number of muscles being used in the power snatch lift. From
the head to the toes there is something happening. Since this movement is sequential in nature,
the majority of the body’s muscles will perform both isometric and isotonic muscular
contractions throughout the 7 phases of the power snatch. This chapter will describe the major
muscles used and their concentric and eccentric actions during each phase of the power snatch.
The importance of good form and stability during this exercise will also be explained.
The following are terms used for the contraction descriptions:
Isometric- Exercise involving no motion and no change in muscle length.
Isotonic- Exercise done with constant muscle contraction.
Concentric contractions- Contraction in which the muscle fibers shorten.
Agonist- Muscle primarily responsible for motion; prime mover.
Eccentric contractions- A lengthening muscle contraction.
Antagonist- Muscles that have an effect opposite to that of movers, or agonists.
Synergists- A muscle aiding in the production of the desired motion.
Definitions and the following muscles and their actions for each
phase described below are sourced from (Hamilton, Luttgens,
Weimar, 2012).
13 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Starting Position
The muscles will be listed starting from the ankles and working up the neck and
shoulders. The lifter is in the starting position for the beginning of the lift. Stability and proper
form to execute the lift is what this position is for. No movement is occurring at this point. The
legs are working at this time to keep the lifter’s body at the proper height to be able to line the
rest of the body up for the lift. Since the lifter is focusing the balance of the body towards the
front of the foot, the tarsal joints are in dorsiflexion which involves the contraction of the tibialis
anterior, peroneus tertius, extensor digitorum longus, and the extensor hallicus longus. The
eccentric muscles involved at the tarsal joints include the tibialis posterior, flexor digitorum
longus, flexor hallucis longus, and the peroneus longus. The ankle dorsiflexion involves the
concentric contraction of the following muscles: [agonist] tibialis anterior, [synergists] peroneus
tertius, extensor digitorum longus, and the extensor hallucis longus. The eccentric muscles
involved in the ankle dorsiflexion are the [antagonist] gastrocnemius, [synergists] soleus, and
peroneus muscles. The flexion of the legs at the knee joint involve the concentric contraction of
the [agonists] hamstrings (biceps femoris, semimembranosus, semitendinosus), [synergists]
sartorius, and gracilis muscles. The eccentric muscles involve the [antagonists] quadriceps
(rectus femoris, vastus intermedius, vastus lateralis, vastus medialis).
The flexion of the thigh at the hip joint involve the concentric contraction of the [agonist]
rectus femoris, [synergists] tensor fascia latae, pectineus, iliopsoas, and sartorius muscles. The
eccentric contractions involve the [antagonists] hamstring muscles. The abduction of the hips
involves the concentric contractions of the [agonists] gluteus medius and minimus. The
eccentric contractions for the abduction of the hips involves the [antagonist] gluteus maximus,
and [synergist] adductor longus. The lateral rotation of the thigh at the hip involves the
14 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT concentric contraction of the [agonist] six deep outward rotators, [syergists] gluteus maximus,
and biceps femoris. The eccentric contractions during the lateral rotation involve the
[antagonists] gluteus medius and minimus. The anterior tilt of the hips involve the concentric
contraction of the [agonist] Iliopsoas, [syergists] pectineus, rectus femoris, Sartorius, tensor
fascia latae, and lumbosacral spinal extensors. The eccentric contractions involve the
[antagonists] hamstrings, gluteus maximus, and lumbosacral spinal flexors.
Since the trunk is to remain straight and tight the entire time, thoracic and spinal muscles
will perform isometric contractions. The primary abdominal muscles used in these contractions
involve the following: Anterior muscles ([cervical region] prevertebral muscles which include
longus capitis & coli, rectus capitis anterior and lateralis; hyoid muscles which include the
suprahyoids & infrahyoids; [thoracic region] Abdominals which include the obliquus externus
and internus abdominus, rectus abdominis, transverse abdominus); Posterior muscles; {Cervical
region] splenius capitis and cervicis, suboccipitals; [Cervical, thoracic, and lumbar region]
erector spinae, deep posterior spinal muscles, semispinalis thoracis, cervicis, and capitis); Lateral
mucles ([Cervical Region] scalenus anterior, posterior, and medius, sternocleidomastoid, and
lavatory scapulae; [lumbar region] quadratus lumborus, psoas major).
The muscles of the shoulder girdle and shoulder joint are also performing isometric
contractions while preparing for the sequential movement. The muscles in the shoulder girdle
involve the following: anterior muscles (pectoralis minor, serratus anterior, subclavius); posterior
muscles (levator scapulae, rhomboids, and trapezius). The muscles of the shoulder joint involve
the following: anterior muscles (pectoralis major, coracobrachialis, subscapularis, biceps
brachii); posterior muscles (infraspinatus, teres minor); superior muscles (deltoid, supraspinatus);
inferior muscles (latissimus dorsi, teres major, longhead of biceps brachii).
15 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT The isometric contracting muscles of the elbow and radioulnar joints involve the
following: the anterior muscles of the elbow (biceps brachii, brachialis, brachioradialis, pronator
teres); anterior muscles of the wrist (pronator quadratus); posterior muscles (triceps brachii,
anconeus, and supinator).
The muscles of the wrist and fingers perform isotonic contractions to grasp the barbell.
The muscles of the wrist include the following: concentric muscles of the wrist ([agonist]flexor
carpi radialis, [synergists] flexor carpi ulnaris, and palmaris longus); eccentric muscles
[antagonists] (extensor carpi radialis brevis, extensor carpi radialis longus, extensor carpi
ulnaris); concentric muscles of the fingers wrapping over the thumb ([agonist] flexor digitorum
profundus, [synergists] flexor digitorum superficialis, flexors digiti minimi brevis, interossei
dorsalis manus, interossei palmaris, lumbricales manus, oppenens digiti minimi, [thumb agonist]
flexor pollicis longus, adductor pollicis, flexor pollicis brevis, opponens pollicis); eccentric
muscles include [antagonist] extensor digitorum, extensor digit minimi, extensor indicis,
abductor digiti minimi, [thumb antagonists] abductor pollicis longus, extensor pollicis brevis,
extensor pollicis longus, abductor pollicis brevis).
Liftoff
The plantar flexion of the tarsal joints include the following concentric muscles: [agonist]
tibialis posterior, [synergists] flexor digitorum longus, flexor halluces longus, and peroneus
longus. The eccentric tarsal muscles include the [antagonists] tibialis anterior, peroneus tertius,
extensor digitorum longus, extensor halluces longus. The gradual ankle plantar flexion involves
the concentric contraction of the following muscles: [agonist] gastrocnemius, [synergists]
soleus, and peroneus muscles. The eccentric muscles involved in the ankle dorsiflexion are the
16 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT [antagonists] tibialis anterior, peroneus tertius, extensor digitorum longus, and the extensor
hallucis longus. The extension of the legs at the knee joint involve the concentric contraction of
the quadriceps ([agonist] rectus femoris, [synergists] vastus intermedius, vastus lateralis, vastus
medialis). The eccentric muscles involve the hamstrings [antagonists] (biceps femoris,
semimembranosus, semitendinosus), Sartorius, and gracilis muscles.
The extension of the thigh at the hip joint involve the concentric contraction of the
[agonist] gluteus maximus and the [synergists] hamstring muscles. The eccentric contractions
involve the [antagonists] iliopsoas, tensor fascia latae, pectineus, rectus femoris, and sartorius
muscles. The abduction of the hips involves the concentric contractions of the [agonists] gluteus
medius and minimus. The eccentric contractions for the abduction of the hips involves the
[antagonists] gluteus maximus and adductor longus. The lateral rotation of the thigh at the hip
involves the concentric contraction of the [agonists] six deep outward rotators, [synergist] biceps
femoris, gluteus maximus. The eccentric contractions during the lateral rotation involve the
[agonists] gluteus medius and minimus. The anterior tilt of the hips involve the concentric
contraction of the hip flexors and lumbosacral spinal extensors. The eccentric contractions
involve the hip extensors and lumbosacral spinal flexors.
Since the trunk is to remain straight and tight the entire time, thoracic and spinal muscles
will perform isometric contractions with a few exceptions for the hip flexion. The primary
abdominal muscles used in these contractions involve the following: Anterior muscles ([cervical
region] prevertebral muscles which include longus capitis & coli, rectus capitis anterior and
lateralis; hyoid muscles which include the suprahyoids & infrahyoids; [thoracic region]
Abdominals which include the [eccentric antagonist] rectus abdominis, obliquus externus and
internus abdominus, transverse abdominus); Posterior muscles; [Cervical region] splenius capitis
17 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT and cervicis, suboccipitals; [Cervical, thoracic, and lumbar region] [concentric agonist] erector
spinae, deep posterior spinal muscles, semispinalis thoracis, cervicis, and capitis); Lateral mucles
([Cervical Region] scalenus anterior, posterior, and medius, sternocleidomastoid, and lavatory
scapulae; [lumbar region] quadratus lumborus, psoas major).
The muscles of the shoulder girdle and shoulder joint are also performing isometric
contractions while preparing for the sequential movement. The muscles in the shoulder girdle
involve the following: anterior muscles (pectoralis minor, serratus anterior, subclavius); posterior
muscles (levator scapulae, rhomboids, and trapezius). The muscles of the shoulder joint involve
the following: anterior muscles (pectoralis major, coracobrachialis, subscapularis, biceps
brachii); posterior muscles (infraspinatus, teres minor); superior muscles (deltoid, supraspinatus);
inferior muscles (latissimus dorsi, teres major, longhead of biceps brachii).
The isometric contracting muscles of the elbow and radioulnar joints involve the
following: the anterior muscles of the elbow (biceps brachii, brachialis, brachioradialis, pronator
teres); anterior muscles of the wrist (pronator quadratus); posterior muscles (triceps brachii,
anconeus, and supinator).
The muscles of the wrist and fingers perform isotonic contractions to grasp the barbell.
The muscles of the wrist include the following: concentric muscles of the wrist ([agonist]flexor
carpi radialis, [synergists] flexor carpi ulnaris, and palmaris longus); eccentric muscles
[antagonists] (extensor carpi radialis brevis, extensor carpi radialis longus, extensor carpi
ulnaris); concentric muscles of the fingers wrapping over the thumb ([agonist] flexor digitorum
profundus, [synergists] flexor digitorum superficialis, flexors digiti minimi brevis, interossei
dorsalis manus, interossei palmaris, lumbricales manus, oppenens digiti minimi, [thumb agonist]
18 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT flexor pollicis longus, adductor pollicis, flexor pollicis brevis, opponens pollicis); eccentric
muscles include [antagonist] extensor digitorum, extensor digit minimi, extensor indicis,
abductor digiti minimi, [thumb antagonists] abductor pollicis longus, extensor pollicis brevis,
extensor pollicis longus, abductor pollicis brevis).
Scoop
The tarsal joints throughout this phase will transition from plantar flexion to dorsiflexion
in preparation for the jump phase. The concentric muscles involved in the dorsiflexion of the
tarsal and ankle joints include the [agonist] tibialis anterior, [synergists] peroneus tertius,
extensor digitorum longus, extensor halluces longs. The eccentric muscles of the tarsal joints
include the [antagonists] tibialis posterior, flexor digitorum longus, flexor halluces longus, and
the peroneus longus. The eccentric contractions of the ankle involve the [antagonists]
gastrocnemius, soleus, and the peroneus. The scooping motion of the thigh underneath the
barbell involve flexion at the knee joint. In relation to the leg at the knee joint, the concentric
contractions include the [agonist] hamstrings, [synergists] sartorius, and gracilis. The eccentric
contractions include the [antagonist] quadriceps. Leading to the slight extension of the leg from
the knees which involve the concentric contraction of the [agonist] quadriceps, and the eccentric
contraction of the [antagonist] hamstrings, Sartorius, and gracilis. The external rotation of the
legs at the knee joint involve the concentric contraction of the [agonist] biceps femoris, as well
as the eccentric contraction of the [antagonists] semimembranosus, semitendinosus, and
popliteus.
The extension of the thigh at the hip joint involve the concentric contraction of the
[agonist] hamstring muscles. The eccentric contractions involve the [antagonists] iliopsoas,
19 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT tensor fascia latae, pectineus, rectus femoris, and sartorius muscles. The abduction of the hips
involves the concentric contractions of the [agonist] gluteus medius and minimus. The eccentric
contractions for the abduction of the hips involves the [antagonist] adductor longus. The lateral
rotation of the thigh at the hip involves the concentric contraction of the [agonist] six deep
outward rotators, biceps femoris, and gluteus maximus. The eccentric contractions during the
lateral rotation involve the [antagonist] gluteus medius and minimus.
The hips are still considered as being in an anterior tilt position, but the degree of tilt
decreases during this phase. This eventually leads the hips to a posterior tilt position during the
jump phase. The anterior tilt of the hips involve the concentric contraction of the hip flexors
(iliopsoas, pectineus, rectus femoris, sartorius, tensor fasciae latae) and lumbosacral spinal
extensors. The eccentric contractions involve the hip extensors (hamstrings, gluteus maximus,
and the six outward rotators) and lumbosacral spinal flexors. For the decrease in the degree of
tilt, the concentric muscles include the hip extensors and lumbosacral spinal flexors. The
eccentric contractions involve the hip flexors and lumbosacral spinal extensors. The abduction
of the hips involves the concentric contractions of the gluteus medius and minimus. The
eccentric contractions for the abduction of the hips involves the adductor longus. The lateral
rotation of the thigh at the hip involves the concentric contraction of the six deep outward
rotators, biceps femoris, and gluteus maximus. The eccentric contractions during the lateral
rotation involve the gluteus medius and minimus.
As the lower body goes through the movements, the upper body is mainly remaining tight
in preparation for the rest of the movements. The proper form demonstrated in the scoop image
is important in keeping the lift efficient. Once again there are a few exceptions to the isometric
contractions. Anterior muscles ([cervical region] prevertebral muscles which include longus
20 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT capitis & coli, rectus capitis anterior and lateralis; hyoid muscles which include the suprahyoids
& infrahyoids; [thoracic region] Abdominals which include the [eccentric antagonist] rectus
abdominis, obliquus externus and internus abdominus, transverse abdominus); Posterior muscles;
[Cervical region] splenius capitis and cervicis, suboccipitals; [Cervical, thoracic, and lumbar
region] [concentric agonist] erector spinae, deep posterior spinal muscles, semispinalis thoracis,
cervicis, and capitis); Lateral mucles ([Cervical Region] scalenus anterior, posterior, and medius,
sternocleidomastoid, and lavatory scapulae; [lumbar region] quadratus lumborus, psoas major).
The muscles of the shoulder girdle and shoulder joint are also performing isometric
contractions for this phase. The muscles in the shoulder girdle involve the following: anterior
muscles (pectoralis minor, serratus anterior, subclavius); posterior muscles (levator scapulae,
rhomboids, and trapezius). The muscles of the shoulder joint involve the following: anterior
muscles ( pectoralis major, coracobrachialis, subscapularis, biceps brachii); posterior muscles
(infraspinatus, teres minor); superior muscles (deltoid, supraspinatus); inferior muscles
(latissimus dorsi, teres major, longhead of biceps brachii).
The isometric contracting muscles of the elbow and radioulnar joints involve the
following: the anterior muscles of the elbow (biceps brachii, brachialis, brachioradialis, pronator
teres); anterior muscles of the wrist (pronator quadratus); posterior muscles (triceps brachii,
anconeus, and supinator).
The muscles of the wrist and fingers perform isotonic contractions to grasp the barbell.
The muscles of the wrist include the following: concentric muscles of the wrist ([agonist]flexor
carpi radialis, [synergists] flexor carpi ulnaris, and palmaris longus); eccentric muscles
[antagonists] (extensor carpi radialis brevis, extensor carpi radialis longus, extensor carpi
21 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT ulnaris); concentric muscles of the fingers wrapping over the thumb ([agonist] flexor digitorum
profundus, [synergists] flexor digitorum superficialis, flexors digiti minimi brevis, interossei
dorsalis manus, interossei palmaris, lumbricales manus, oppenens digiti minimi, [thumb agonist]
flexor pollicis longus, adductor pollicis, flexor pollicis brevis, opponens pollicis); eccentric
muscles include [antagonist] extensor digitorum, extensor digit minimi, extensor indicis,
abductor digiti minimi, [thumb antagonists] abductor pollicis longus, extensor pollicis brevis,
extensor pollicis longus, abductor pollicis brevis).
Jump
The jump phase involves the plantar flexion and supination of the tarsal joints. The
plantar flexion includes the concentric contractions of the [agonist] tibialis anterior, [synergists]
peroneus tertius, extensor digitorum longus, extensor halluces longs. The eccentric muscles of
the tarsal joints include the [antagonists] tibialis posterior, flexor digitorum longus, flexor
halluces longus, and the peroneus longus. The supination of the tarsal joints involve the
concentric contractions of the [agonist] tibialis posterior, as well as the eccentric contraction of
the [antagonists] peroneus longus, brevis and tertius.
The extension of the legs at the knee joint involve the concentric contraction of the
quadriceps ([agonist] rectus femoris, [synergists] vastus intermedius, vastus lateralis, vastus
medialis). The eccentric muscles involve the [antagonists] hamstrings (biceps femoris,
semimembranosus, semitendinosus), Sartorius, and gracilis muscles. The extension of the thigh
at the hip joint involve the concentric contraction of the [agonists] hamstring muscles. The
eccentric contractions involve the [antagonists] iliopsoas, tensor fascia latae, pectineus, rectus
femoris, and sartorius muscles.
The abduction of the hips involves the concentric contractions
22 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT of the [agonists] gluteus medius and minimus. The eccentric contractions for the abduction of
the hips involves the [antagonists] adductor longus. The extension of the hips involves the
concentric contraction of the [agonists] gluteus maximus, hamstrings, and [synergists]
lumbosacral spinal extensors. The eccentric contractions for the hip extension involves the
[antagonists] iliopsoas, hip flexors, and lumbosacral spinal extensors. The extension of the
thoracic and lumbar spine include the concentric contractions of the [agonist] erector spinae,
semispinalis thoracis, and deep posterior spinal muscles. The eccentric contractions include the
abdominals. The extension of the cervical spine and atlanto-occipital joint involve the concentric
contractions of the [agonist] erector spinae capitis & cervicis, splenius capitis & cervicis, semi
spinalis, deep posterior spinal muscles, and suboccipitals. The eccentric contractions include the
[antagonists] sternocleidomastoid, scalenes, and prevertebral muscles.
The muscles in the shoulder girdle while the bar is propelled up involve the concentric
contraction of the [agonist] trapezius, [synergists] levator scapulae, rhomboids major and minor,
and the serratus anterior. The eccentric contractions of the shoulder girdle include the
[antagonists] pectoralis minor, subclavius. The muscles of the shoulder joint involve the
concentric contraction of the [agonist] deltoid (anterior, middle, posterior), pectoralis major
(clavicular, sternal), [synergists] subscapularis, supraspinatus, infraspinatus and teres minor, and
latissimus dorsi. The eccentric contractions of the shoulder joint involve the [antagonists] teres
major, triceps brachii, pectoralis, biceps brachii, and the coracobrachialis.
The muscles involved in the flexion of the elbow and radioulnar joints involve the
concentric contraction of the [agonist] biceps brachii, brachialis, brachioradialis, pronator teres,
and the pronator quadratus. The eccentric actions include the [antagonist] biceps brachii, triceps
brachii, supinator, and the anconeus.
23 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT The muscles of the wrist and fingers perform isotonic contractions to grasp the barbell.
The muscles of the wrist include the following: concentric muscles of the wrist ([agonist]flexor
carpi radialis, [synergists] flexor carpi ulnaris, and palmaris longus); eccentric muscles
[antagonists] (extensor carpi radialis brevis, extensor carpi radialis longus, extensor carpi
ulnaris); concentric muscles of the fingers wrapping over the thumb ([agonist] flexor digitorum
profundus, [synergists] flexor digitorum superficialis, flexors digiti minimi brevis, interossei
dorsalis manus, interossei palmaris, lumbricales manus, oppenens digiti minimi, [thumb agonist]
flexor pollicis longus, adductor pollicis, flexor pollicis brevis, opponens pollicis); eccentric
muscles include [antagonist] extensor digitorum, extensor digit minimi, extensor indicis,
abductor digiti minimi, [thumb antagonists] abductor pollicis longus, extensor pollicis brevis,
extensor pollicis longus, abductor pollicis brevis).
Pull-Under
The concentric muscles involved in the dorsiflexion of the tarsal and ankle include the
tibialis anterior, peroneus tertius, extensor digitorum longus, extensor halluces longs. The
eccentric muscles of the tarsal joints include the tibialis posterior, flexor digitorum longus, flexor
halluces longus, and the peroneus longus. The eccentric contractions in relation to the ankle
involve the astrocnemius, soleus, and peroneus. In relation to the flexion of the leg at the knee
joint, the concentric contractions include the hamstrings, sartorius, and gracilis. The eccentric
contractions include the quadriceps. The external rotation of the legs at the knee joint involve
the concentric contraction of the biceps femoris, as well as the eccentric contraction of the
semimembranosus, semitendinosus, and popliteus.
24 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT The anterior tilt/ flexion of the hips involve the concentric contraction of the hip flexors
(iliopsoas, pectineus, rectus femoris, sartorius, tensor fasciae latae) and lumbosacral spinal
extensors. The eccentric contractions involve the hip extensors (hamstrings, gluteus maximus,
and the six outward rotators) and lumbosacral spinal flexors. The hyper extension of the thoracic
and lumbar spine involves the concentric contraction of the erector spinae, semispinalis thoracis,
and the deep posterior spinal muscles. The eccentric contractions involve the abdominals. If
you notice in the image for this movement, the lifter appears to be extending her neck to clear the
barbell. These concentric contractions of the cervical spine and atlanto-occipital joint involve
the spenius capitis & cervicis, erector spinae capitis & cervicis, semispinalis, deep posterior
spinal muscles, and the suboccipitals. The eccentric contractions involve the
sternocleidomastoid scalenes, and the prevertebral muscles.
The muscles in the shoulder girdle involve the concentric contraction of the trapezius,
levator scapulae, rhomboids major and minor, and the serratus anterior. The eccentric
contractions of the shoulder girdle include the pectoralis minor, subclavius. The muscles of the
shoulder joint involve the concentric contraction of the pectoralis major (clavicular, sternal),
deltoid (anterior, middle, posterior), subscapularis, supraspinatus, infraspinatus and teres minor,
and latissimus dorsi. The eccentric contractions of the shoulder joint involve the teres major,
triceps brachii, pectoralis, biceps brachii, and the coracobrachialis.
The muscles of the elbow and radioulnar joints during flexion involve the concentric
contraction of the biceps brachii, brachialis, brachioradialis, pronator teres, and the pronator
quadratus. The eccentric actions include the biceps brachii, triceps brachii, supinator, and the
anconeus. The muscles of the wrist in flexion involve the flexor carpi radialis, flexor carpi
ulnaris, and palmaris longus. The eccentric muscles involved are the extensor carpi radialis
25 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT brevis, extensor carpi radialis longus, extensor carpi ulnaris. The concentric muscles involved in
the flexion of the fingers are flexor digitorum profundus, flexor digitorum superficialis, flexors
digiti minimi brevis, interossei dorsalis manus, interossei palmaris, lumbricales manus, oppenens
digiti minimi, flexor pollicis longus, adductor pollicis, flexor pollicis brevis, opponens pollicis.
The eccentric muscles include extensor digit minimi, extensor digitorum, extensor indicis,
abductor digiti minimi, abductor pollicis longus, extensor pollicis brevis, extensor pollicis
longus, and the abductor pollicis brevis.
Catch
The concentric muscles involved in the dorsiflexion of the tarsals and ankle joints include
the tibialis anterior, peroneus tertius, extensor digitorum longus, extensor halluces longs. The
eccentric muscles of the tarsal joints include the tibialis posterior, flexor digitorum longus, flexor
halluces longus, and the peroneus longus. The eccentric contractions in relation to the ankle
involve the gastrocnemius, soleus, and peroneus. In relation to the flexion of the leg at the knee
joint, the concentric contractions include the hamstrings, sartorius, and gracilis. The eccentric
contractions include the quadriceps. The external rotation of the legs at the knee joint involve
the concentric contraction of the biceps femoris, as well as the eccentric contraction of the
semimembranosus, semitendinosus, and popliteus.
The anterior tilt/ flexion of the hips involve the concentric contraction of the hip flexors
(iliopsoas, pectineus, rectus femoris, sartorius, tensor fasciae latae) and lumbosacral spinal
extensors. The eccentric contractions involve the hip extensors (hamstrings, gluteus maximus,
and the six outward rotators) and lumbosacral spinal flexors. The extension of the thoracic and
hyper extension of the lumbar spine involve the concentric contraction of the erector spinae,
26 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT semispinalis thoracis, and the deep posterior spinal muscles. The eccentric contractions involve
the abdominals.
The muscles of the shoulder girdle involved in concentric contractions are the [agonist]
trapezius II and IV and the serratus anterior. The eccentric muscles involved are the [antagonist]
rhomboids and pectoralis minor. The muscles involved in the concentric contraction of the
shoulder joint are the [agonist] deltoids, pectoralis major (clavicular) and supraspinatus. The
eccentric muscles involved are the [antagonists] latissimus dorsi, teres major, pectoralis major
(sternal), and posterior deltoid.
The movements for the extension of the forearm involve the concentric contraction of the
[agonist] triceps brachii and the anconeus. The eccentric contractions involve the [antagonist]
biceps brachii, brachioradialis, and brachialis. The pronation of the forearm involve the
concentric contraction of the [agonists] pronator teres and pronator quadratus. The eccentric
contractions involve the [antagonists] supinator and the biceps brachii. The muscles of the wrist
in flexion involve the flexor carpi radialis, flexor carpi ulnaris, and palmaris longus. The
eccentric muscles involved are the extensor carpi radialis brevis, extensor carpi radialis longus,
extensor carpi ulnaris. The concentric muscles involved in the flexion of the fingers are flexor
digitorum profundus, flexor digitorum superficialis, flexors digiti minimi brevis, interossei
dorsalis manus, interossei palmaris, lumbricales manus, oppenens digiti minimi, flexor pollicis
longus, adductor pollicis, flexor pollicis brevis, opponens pollicis. The eccentric muscles include
extensor digit minimi, extensor digitorum, extensor indicis, abductor digiti minimi, abductor
pollicis longus, extensor pollicis brevis, extensor pollicis longus, and the abductor pollicis brevis.
27 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Biomechanics
Using proper form and technique is something that should be done with any physical
activity. Knowing the proper way to lift or move is what prevents injury and promotes progress.
“The primary factors that affect the success of weightlifters in the snatch technique of
weightlifting are explosive strength, flexibility, and as well as technique” (Alptekin, Harbili,
2014). Of these three, technique is what promotes strength. Consider a slingshot, the handle is
your technique, and the strength is the rubber band, and the rock is your progress. The stronger
your technique, the farther you can push your limits (rubber band), leading to more progress. If
the slingshot’s handle were made of flimsy plastic, your progress in improving strength would be
compromised because of a poor foundation.
What makes this lift so unique is not only the complexity, but how the movements
evolved in order to increase performance. Record setting lifters found that it was much more
efficient to move the body around the bar instead of moving the bar around the body (Newton,
2002). According to Newton, scientists discovered a certain barbell pattern to be in the shape of
an elongated S, because lifters found that keeping the bar as close to the body as possible during
the lift provided positive results. Research has shown “that the mechanical work was greater in
the first pull than the mechanical work in the second pull, and on the contrary, the power output
was greater in the second pull than in the first pull” (Harbili, 2012). This showing that good
form can prove a difference between power (jump phase) and strength (liftoff).
When lifting heavy weights, the potential for serious injury increases with more weight.
So knowing how to execute the seven phases of this movement properly will help prevent any
small error that could lead to a failed lift (Newton, 2002). The proper flexibility will also make it
28 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT easier to execute more mobility demanding phases such as the catch. As far as corrections go,
the weightlifting sport has evolved this movement to its maximum efficiency. From the starting
position to the recovery the spinal column is maintained in a neutral position reducing stress on
the spine, while the bar maintains constant momentum until the catch and recovery phase.
Barbell Path Breakdown
Graph Obtained From: (Alptekin,Harbili, 2014)
29 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Chapter III
The major muscles used in the power snatch are the ankle flexors and extensors,
quadriceps, hamstrings, hip flexors and extensors, abdominals, biceps brachii, triceps brachii,
deltoids, trapezius, pectoralis muscles, and the wrist, finger, and thumb flexors and extensors.
The ankle flexors and extensors, quadriceps, hamstrings, and the hip flexors and extensors are
the power of the lift. These muscles are the ones responsible for getting the weight off of the
ground and projecting it to a point where the lifter can pull themselves under the bar for the catch
(Newton, 2002). The abdominals are very important in terms of biomechanics. Remember the
sling shot? The abdominals represent the strong handle. By keeping the core straight and the
body balanced; these stabilizing muscles allow the lifter to manipulate the barbell more
efficiently, effectively, and safely when used properly during the power snatch lift. The
trapezius is responsible for the first strong concentric contraction of the shoulder region during
the jump phase (Newton, 2002). The biceps brachii, triceps brachii, deltoids, and pectoralis
muscles are responsible for pulling the body under the bar and locking out the arms to support
the barbell during the catch and recovery stage. The thumb flexor and abductors allow the lifter
to take advantage of the hook grip, which can add up to 10% more weight to a lifter’s pull
(Newton, 2002). The finger and wrist flexors and extensors are used to lock the fingers around
the thumb and properly grasp the bar in preparation for the power snatch lift.
The exercises used to improve the power snatch include the following recommendation:
Complementary exercises that have movement patterns similar to the competitive
lifts (e.g. hang/power snatch, snatch pulls, front and back squats) and supporting
30 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT exercises (e.g. overhead presses, back extensions, and abdominal work) that target
synergistic muscle groups are also used (Smith, Storey, 2012).
Also overhead squats are important in training for the power snatch lift. The other important
factor in training for the power snatch is to work on mobilization. Since the ankles, knees, and
hips are the main power sources for the lift, they should be flexible in order to make the lift safer
and more efficient. The shoulders are another part of the body that needs to have the proper
mobilization in order for the lifter to stabilize the bar over their heads without losing their
balance during the catch and recovery phases. The mobilization should be done before and after
the lifter’s workout.
The first exercise we will discuss is the overhead press. This exercise helps increase the
lifter’s shoulder, arm, and core strength, and also gives them confidence in holding heavy weight
above their head. This exercise begins with a barbell resting on the shoulders behind the neck
and then pressing the bar up keeping the bar over the midpoint of the body (Newton, 2002).
The next exercise is the back or front squat. This exercise helps strengthen the gluteus
maximus, hamstrings, and quadriceps. This is where the lifter places the bar either on the back
of their shoulders, or in front of their neck with the bar resting on the anterior portion of the
shoulders. The lifter will then lower their body by bending at the hips, knees, and ankles while
keeping the back straight, chest up, and head neutral. They will lower until their knees pass 90
degrees of flexion and then raise back to standing. This will help the lifter understand the
importance of keeping their back straight, as well as the importance of hip and ankle mobility
(Newton, 2002).
31 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT The next exercise is the back extension, which is used to strengthen the lower back
muscles. The movement begins with the lifter positioned with their back extended and then the
lifter will flex their hip joints lowering the torso towards the floor until perpendicular to the
floor. It is important for the lifter to keep their back straight while doing this (Newton, 2002).
Here is an image of the bench used for this exercise.
The next exercise is the sit up, which is used to strengthen the abdominal muscles. The
position begins with the lifter laying on the floor with the knees bent at a 45 degree angle. The
32 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT lifter will then place their hands on top of the head and raising their torso perpendicular to the
floor.
The next exercise is the overhead squat. This will increase the lifters confidence in the
pull under and catch phases by working the muscles in the hips, legs, core, shoulders and arms.
The lifter will press the bar above their heads and perform a proper squat. This will also help the
lifter understand the importance of shoulder mobility as well. If the lifter has tight shoulders, it
will be extremely difficult to complete a full squat while holding a barbell above the head.
Snatch pulls are the next exercise the lifter should work on. This is a difficult technique
to master so usually a pvc pipe is used during the warm up, and then training begins with actual
weighted bars. This will help strengthen the hip extensors, knee extensors, ankle extensors, and
the trapezius. There are three ways to do this exercise. The high hang, low hang, and full snatch
pull. The high hang involves lifting blocks suspending the barbell to the level of the mid thighs.
Stand in the power position, and jump explosively pulling the bar up to the sternum keeping the
elbows pointed towards the ceiling (Newton, 2002).
The low hang snatch pull involves lowing the lifting blocks to where the bar is positioned
right below the knees. This will help with getting the lifter used to the scooping motion of the
scoop phase and transitioning to the jump phase. The lifter will pull their shoulders up, scoop
the bar to the hips and jump explosively upwards, shrugging and pulling the bar to the sternum
(Newton, 2002).
The full snatch pull is from the floor, and its purpose it to get the lifter used to the
transitions between the starting position, liftoff, scoop, and jump phase. The standard motions
33 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT will be executed resulting in the lifter explosively pulling the barbell to the sternum level
(Newton, 2002).
The hang power snatch is the next exercise used to combine all of the previous exercises
into one continuous motion. This will help the lifter get comfortable with the pull under, catch,
and recovery phases. Starting off with the barbell just below the knees, scooping the bar to the
hips, explosively jumping to propel the bar to the pull under phase. The lifter will pull
themselves under the bar and into a half squat stance catching the barbell overhead. The lifter
will then extend the legs holding the bar overhead into the recovery position (Newton, 2002).
These exercises are progressive in nature. Starting from the basic requirements of the
exercise. Being comfortable with the fundamentals of the basic back and front squat and
progressing to the overhead squat. This will enforce the importance of maintaining proper
mobility in the ankles, knees, hips, and shoulders. The abdominals are important in stability, so
keeping them strong will help keep the lifter balanced throughout the lift. The progressions of
the snatch exercises begins from the most significant portion of the lift, the jump phase. This is
because this phase is the most difficult to master. Once the lifter is comfortable with that
movement, the bar will get closer to the starting position solidifying the fundamentals of the lift.
Once the fundamentals of the lift have been established and the lifter is competent in their ability
to execute a safe, efficient, and effective snatch pull from the floor, then they will be ready to
work on the pull under, catch, and recovery phases of the power snatch.
34 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT Conclusion
The purpose of this lift is not only to improve the lifters lifting capabilities, but to solidify
the importance of proper biomechanics. Proper biomechanics are solidified significantly while
learning how to execute a power snatch successfully. Most lifters will focus on using their
strength to get the barbell over the head instead of pulling their body underneath. This not only
results in a lesser weight being lifted, but more often a failed lift. One instance of inferior
biomechanics in any one of the seven phases has the capability to compromise the lift as a whole.
As mentioned earlier, there is also a difference between strength and power. The strength
portion of the lift is during the liftoff phase, which leads directly to the most significant power
portion of the lift; the jump phase. Using the proper form to pull the body directly under the bar
for the catch offers the lifter the chance to simply manipulate their own body weight to do this.
Since the weight of the barbell could possibly be more than the lifters own weight, this give the
lifter a significant advantage in executing the lift successfully. The strength aspect of the lift is
then left for the lifter to not only hold a challenging weight above their head, but to maintain
their stability while transitioning from the catch to the recovery phase with their lower body,
abdominal, and shoulder strength. The power snatch gives the lifter the ability to understand
how using technical biomechanics, as well as their strength and power in harmony will help them
push their maximum efforts past what they thought they were capable of doing. As a result this
understanding will assist the lifter vastly improve their maximum lifting capacities in other
exercises.
35 Running Head: MUSCULAR ANALYSIS OF THE POWER SNATCH LIFT References
Behnke, R. (2012). Kinetic Anatomy (3rd ed.). Champaign, IL: Human Kinetics.
Collet, C., Guillot, A., Bolliet, O., & Dittmar, A. (2006). Autonomic-Nervous-System Activity During
the Preparation Phase for the Snatch in Olympic Weight Lifting. International Journal of
Sports Physiology and Performance, 375-387.
Hamilton, N., Weimar, W., & Luttgens, K. (2012). Kinesiology: Scientific Basis of Human
Motion (12th ed., pp. 1-207). New York, New York: McGraw-Hill.
Harbili, E. (2012). A Gender-Based Kinematic and Kinetic Analysis of the Snatch Lift in Elite WeightLifters in 69-kg Category. Journal of Sports Science and Medicine, (11), 162-169.
Harbili, E., & Alptekin, A. (2014). Comparative Kinematic Analysis of the Snatch Lifts in Elite Male
Adolescent Weightlifters. Journal of Sports Science and Medicine, (13), 417-422.
Lee, Y., Huwang, C., & Tsuang, Y. (1995). Biomechanical Characteristics of Preactivation and
Pulling Phases of Snatch Lift. Journal of Applied Biomechanics, (11), 288-298.
Newton, H. (2002). Explosive Lifting for Sports (pp. 40-50, 61-76). Champaign, IL: Human Kinetics.
Rossi, S., Buford, T., Smith, D., Kennel, R., Haff, E., & Haff, G. (2007). Bilateral Comparison of
Barbell Kinetics and Kinematics During a Weightlifting Competition. International Journal of
Sports Physiology and Performance, (2), 150-158.
Sato, K., Sands, W., & Stone, M. (2012). The Reliability of Accelerometry to Measure Weightlifting
Performance. Sports Biomechanics, 4(11), 524-531.
Storey, A., & Smith, H. (2012). Unique Aspects of Competitive Weightlifting Performance, Training
and Physiology. Sports Med, 42(9), 769-790.
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