Download How many bones are there in the human body? The skeleton has 5

How many bones are there in the human body?
The skeleton has 5 functions. Write in below what they are:
a)
S
d)
M
b)
S
e)
Making B
c)
P
C
There are 4 different types of bones.
List below what they are and give 2 examples for each type.
a)
L
Examples
b)
S
Examples
c)
F
Examples
d)
I
Examples
Write down the technical name for each of the following bones.
a)
Lower jaw
d)
Skull
b)
Collarbone
e)
Kneecap
c)
Shoulder blade
f)
Breastbone
Using words from the box below complete the following sentences.
Shell, red blood cells, white blood cells, periosteum, jelly, ossification,
maturity, cartilage, fat, sponge, red marrow, yellow marrow, blue marrow
All bones start as
. Over time they turn to bone through
the process of
. The tough outer layer of bone is called
the
and at each end of the bone is a layer of
The spongy part of the bone contains
are made. The marrow cavity contains
where
are formed.
where
.
Use the list of muscles to label the diagram. Gastrocnemius, biceps, latissimus-dorsi,
abdominals, deltoids, gluteals, quadriceps, hamstrings, triceps, trapezius, pectorals
There are 3 different types of muscle in the body. Use a rule to draw straight lines to
match the descriptions to the correct muscle type.
Cardiac
Attached to the skeleton to make
movement. Under our conscious control.
Involuntary
Found only in the heart. Work
continuously without our conscious
control.
Found around internal organs. Work
without our conscious control.
Complete the sentences below using the words from the box.
Involuntary
Contract, more, different, string, relax, nervous system, fibres, similar,
impulse, less, slow-twitch, fast-twitch
Muscles are made up of
. Everyone has a
number of muscle fibres, but some have more of one type than the other.
There are 2 types of muscle fibres:
and
.
A muscle will
Fitter people have
when it receives an
.
muscle fibres ready to be used. The nerve
impulses and the muscles are coordinated by the
.
Muscles are attached to two bones by tendons. Complete the sentences below to
identify which is the origin and which is the insertion of a muscle.
a)
The origin attaches the muscle to the
bone.
b)
The insertion attaches the muscle to the
bone.
Complete the sentences below using the words from the box.
pairs, push, pull, biceps, antagonistic, synergist, triceps, contracts, relaxes,
threes, prime mover, agonist, lift, antagonist, worker, lazy
Muscles always work in
and not
because they can only
. These pairs are known as
muscles. For
movement to occur, one muscle shortens (
muscle lengthens (
the
), whilst the other
). The muscle that contracts is known as
or
muscle. The muscle that
relaxes is known as the
muscle. Muscles which hold the
bone in place are known as
muscles.
Draw straight lines to match the condition to the causes.
Muscle Fatigue
Muscle Atrophy
Cramp
Muscle Tone
Caused by lack of exercise
Caused by lack of oxygen or overuse
Caused by tension in the muscle
Caused by a sudden contraction of
muscle that won’t relax
Outline the major differences in muscle length between an isometric and isotonic
contraction.
Complete the table below to explain what happens as the elbow bends and
straightens. Use these words: contracts/relaxes/biceps/triceps. (You can use each
more than once.)
Movement
Biceps
Triceps
Prime Mover
Antagonist
phase
Elbow
bends
Elbow
straightens
Complete the sentences below to explain what the respiratory system does.
The respiratory system supplies our bodies with
We breathe air into our
our
.
and the oxygen is then transferred into
. It is then carried all around our body.
Put the following words into the correct order to show the pathway of air in through the
respiratory system: bronchioles, nose or mouth, gas exchange, alveoli, bronchi, trachea
1.
2.
3.
4.
5.
6.
Tick the correct answer in each of the following statements.
Gaseous exchange takes place in the …
Nasal cavity

Alveoli

Heart 

Millions 
How many alveoli are there in the lungs?
None

Twenty six
The haemoglobin in the red blood cells combine with oxygen to make…
Oxyhaemoglobin
haemo-oxygen

carbon dioxide
The oxygen is carried around the body by red blood cells. However the blood also
picks up cardon dioxide and takes it back to the …
Diaphram

Lungs

Villi

Write a few short sentences to describe the difference between the air we breathe in
and the air we breathe out.
Complete the sentences below to explain what happens when we breathe in and
breathe out.
Breathing in is known as
. The diaphragm and intercostals muscles
, increasing the capacity of the chest
.
Because of the difference in air pressure, air rushes into the
.
Breathing out is known as
muscles
. The diaphragm and intercostals
, making the chest cavity
compresses the lungs and air is forced
. This
.
Draw straight lines to match the definitions with the correct lung capacity.
Tidal Volume
The maximum amount of air you can
breathe in or out in one breath.
Inspiratory Capacity
The amount of air left in the lungs after
you have breathed out as much as you
possibly can.
Expiratory Reserve Volume
The actual amount of air breathed in (or
out) in one breath.
Vital Capacity
The amount of air you can forcibly
breathe out after breathing out normally.
Residual Volume
The maximum amount of air you can
breathe in after breathing out
List 3 immediate effects on the respiratory system caused by exercise
1.
2.
3.
Write down a definition of VO2 Max and explain how you can improve it.
Definition:
How to improve it:
Complete the sentences below using words from the box.
Stretching, warm up, size, temperature, heart, movement, injury,
shower, focused, muscles
Before taking part in any physical exercise, everyone should
By increasing the
.
of the body and increasing blood flow to
the
, the body becomes better prepared for exercise.
the muscles not only increases the range of
also means the athlete is less likely to get a muscle
, it
. As well
as the body being physically prepared, a good warm up also helps the mind to become
more
.
After physical exercise, a “cool down’ should be performed.
Tick the boxes below that indicate reasons why we cool down.

Help repay oxygen debt.
 Get rid of unused energy.

Prevent blood pooling .
 To build muscle.

To increase lung capacity.
 To stop muscle stiffness.

 Help return body systems to normal.
Help remove lactic acid and
other waste products.
Each one of the following are important elements of a training session.
For each one write down why they are important.
1. Warm up
2. Variety
3. Regular testing and reviewing
SPOR is the acronym used to help remind you of the 4 principles of training.
Write down the principle each letter stands for. Explain what is meant by each term.
S
Meaning
P
Meaning
O
Meaning
R
Meaning
Three pathways provide energy for physical activity. Two are anaerobic (without
oxygen), and the other aerobic (with oxygen):



Aerobic system.
Anaerobic lactic acid system.
Anaerobic CP (Phospho-creatine) system.
The type of energy pathway used is dependent on the type of activity performed.

Activity that is longer in duration and of low intensity is fuelled by the
aerobic energy system.
E.g.

Activity that is shorter in duration and of higher intensity is fuelled by the
anaerobic energy systems.
E.g.
The three energy systems overlap and sometimes combine to power all human
movement.
Graph: The three energy pathways used by the body to fuel
physical activity
Phospho-creatine system
Anaerobic lactic acid system
Energy
Contribution
(%)
Aerobic system
0
20
60
140
300
Time (seconds)
620
260
Note: Axis not to scale
Anaerobic CP system
The anaerobic CP system is used for very short duration, high intensity activity
typically lasting up to 30 seconds. Energy is supplied to the body through the
consumption of creatine phosphate. There are no by-products with this energy system
and it keeps going until all the stored energy is used up, at which point performance
suffers. This energy pathway replenishes after 2-3 minutes, then short-duration, highintensity activity can continue for another 30 seconds.
Activities that use this energy system include:
Anaerobic lactic acid system
The anaerobic lactic acid system is used for shorter duration, high-intensity activity
typically lasting between 30-90 seconds. Energy is supplied through the consumption
of carbohydrate. This causes the build up of lactic acid, which eventually causes
performance to decrease. At this point the person either lowers their intensity or
allows the aerobic system to continue fuelling the exercise, or they stop exercising
completely.
Activities that use this energy system include team games where high intensity
activity is performed for short periods of time.
E.g.
Aerobic system
Energy is supplied to the body through the consumption of oxygen. This combines
with lactic acid to produce water, therefore there is no effect on performance.
Activities that use this system include:
On a separate page summarise the information above. Use a full page. Set it out
in “Landscape” form. Begin with Energy systems in the middle; add the 3
energy systems; then summarise info, finally add examples.
Use Colour, add sketches……
Complete the table for the Olympic track and field events, identifying which of the
three energy systems is being used in the event most of the time.
Event
Aerobic
(endurance
over 90 seconds
duration)
Anaerobic lactic
(speed, strength,
15 – 90 seconds
duration)
Phospho-creatine
(speed, power, less
than 15 seconds
duration)
100m sprint
Marathon
Triple jump
400m
Long jump
50 km walk
800m
Javelin
High jump
Shot put
Pole vault
Discus
3000m
Explain the energy systems that are used in performing a 40 km cycle race.
Energy Systems & Sport
Muscular action derives energy from three separate systems. Different sports may require the
development of one of these systems or all three and knowledge of these mechanisms allows
training to be specific to your needs. All working muscles require ATP (adenosine
triphosphate), a compound which has a central molecule linked by three high energy
phosphate bonds. Energy is provided in liberating one of these bonds, and it is the constant
supply of ATP that determines muscular performance.
A limited amount of ATP exists in muscle cells linked to another molecule called
phosphocreatine (PC). This combination is named ATP-PC. This can provide a brief,
approximately 30 seconds only, intense muscular contraction. This mechanism is anaerobic
so requires no oxygen, and does not cause a build-up of toxins like lactic acid. This
mechanism is the first supply of ATP and obviously is only useful for short muscular bursts or
sudden movement. This mechanism is involved in short sharp actions such as power lifts,
throws or short sprints.
A second source of energy is glycolysis. This is also an anaerobic system, and also known
as the lactic acid system. Here muscle glycogen is used as fuel initially, but blood glucose
and liver glycogen can be drawn upon to produce ATP. This system requires a series of
chemical reaction to occur and produces lactic acid as a breakdown product. It lasts longer,
up to 5 minutes, but lactic acid build up in muscle inhibits efficient contraction and causes the
familiar "burning" feeling in a near exhausted muscle. Interval training, short near maximal
bursts initiates this system, and trains your body to tolerate lactic acid build-up and to develop
this mechanism. This system is used in a sprint in cycling and may be used for intense
periods in a game like rugby. A problem with the lactic acid system is that the lactic acid
needs to be removed and metabolized by the body, procedures which both consume energy.
Thus endurance athletes should avoid using this system except perhaps at the very end of an
event.
The third source is the aerobic system, and this also uses glycogen and glucose as energy
sources. It also requires oxygen so needs a good heart, lung and circulatory system. This is
the system which supplies long term energy, and is the major supplier of energy for any effort
over 5 minutes. These three systems operate together depending on the effort required, the
body using the aerobic system primarily and saving anaerobic power for sudden or extreme
needs. An endurance athlete should avoid using anaerobic system because lactic acid may
interfere with muscles action. The point at which lactic acid becomes debilitating is called the
anaerobic threshold (AT), and can be measured to monitor changes in an individual’s
fitness. The other way of measuring the aerobic system is to measure V02 max., the amount
of oxygen your body utilizes at a maximal sustainable effort. Depending on the sport involved,
one or all of these systems may be used. Some sports may concentrate on one system, and
actively avoid using the other, typically the aerobic endurance athlete avoiding the lactic acid
system. Other sports may require more flexible energy sources; a racing cyclist needs an
excellent aerobic base, but needs to be able to sprint briefly and repeatedly using the
anaerobic system. For this individual the training should mimic this and utilize "interval"
techniques. Again, sports involving primarily strength or a sudden effort may require strength
and speed training of the muscles involved. This develops the anaerobic systems primarily. At
the end of the day however, all of this can be summed up by the word "specific". To be
successful you training must be "specific", and mimic the sport in which you wish to succeed.
Training that is not "specific" and develops inappropriate energy systems may be actually
detrimental to performance in your chosen sport.
Quality Training
If you are training to compete, you want to maximize training time but if taken to excess, over
training or injury will result in decreased performance. Quality of training is much more
important at higher levels of competition than quantity. Quality training is defined as training
that is intense enough to stimulate a training response (i.e. more muscle power, more aerobic
capacity) but training must also be specific. By specific we mean that it will encourage your
body to improve in the direction that will give the performance gain you desire. An example of
training that is non specific is for a 100m sprinter to do long endurance runs. The long runs
will stimulate an increase in aerobic energy systems and more slow-twitch muscle fibre. Both
these adaptations will increase distance endurance but will be at the cost of sprinting ability
which uses fast-twitch fibres and anaerobic energy systems. The result of long distance
training may well be to decrease sprinting performance, not improve it. Training that closely
mimics your event will always be specific, so the distance runner can train distance running
and know that it is appropriate. However, it is boring and not always possible to train as you
would compete. Team players must train on their own. Marathon runners are not going to run
marathons to train.
For variety many may wish to train in a gym, pool or on a bike to maintain interest or reduce
the possibility of injury. In this cross-training situation care is needed to keep the training
specific. Questions that need to be asked are: Am I training the energy systems appropriate
to my sport? (See energy systems article.) Am I training the muscle groups appropriate to my
sport? Will the training enhance skills technique or motor patters to improve my performance?
If the answer is positive to these questions then the training is probably suitable. An example
of appropriate training could be a front row forward and swimming. Ideally swimming would
include fast sprint lengths with rest lengths. This would enhance upper body strength, the
short sharp sprints simulating the bursts of power needed in a rugby game. Some sports
demand skill or motor patterns above all; golf and tennis good examples. Strengthening the
upper body with weights can increase power and the degree of control but care must not be
taken to disturb finely honed movement patterns. Because muscles fire in step-wise
accumulation of motor units to provide a smooth controlled contraction, a bigger stronger
muscle will always provide smoother more accurate control, than a weak muscle. Because of
this, a strong well adapted muscle will provide the better golf or tennis stroke, but relearning
of movement patterns also needs to occur along with muscle development.
Training is not a simple matter of more and harder, which often leads to fatigue, over training
or injury. For a competitive athlete a great deal of thought needs to be put into training
regimes, the wrong training can be more harmful than no training, “Quality” training must be
both intense and specific and must take account of skills or movement patterns. If confused,
seek advice. Coaches, gym instructors may give good recommendations. If unsure, come and
see us at Gloucester Sports Clinic.
Dr Neil Averis
1. What is the compound that all working muscles require to release energy?
2. Describe the ATP-PC system.
3. Give 3 examples of actions where the ATP-PC system is the sole energy
provider.
4. Describe the anaerobic glycolysis system.
5. What is the “burning” feeling in a near exhausted muscle due to?
6. Give 5 specific examples where this energy system would be used during an
event or game.
7. Why should endurance athletes avoid using this system except perhaps at the
very end of an event?
8. How is lactic acid removed / expelled from the body?
9. Describe the aerobic energy system.
10. What is the anaerobic threshold?
11. What is VO2 max?
12. Describe how a racing cyclist would need all 3 energy systems.
13. Describe the energy system(s) used in a “probo” session at Pro-fitness.
14. Describe the energy systems used during a 20 minute training run.
15. Describe why a 100m sprinter should probably avoid long endurance runs.
16. Explain how swimming could be a useful form of training for a front row
forward in rugby.
17. Explain how a bigger, strong muscle can provide a better golf or tennis stroke.
Kit’s Physical Education class were investigating the response of the heart and lungs
to exercise. They recorded Kit’s heart rate and breathing frequency before and during
a 20 minute run.
Resting heart rate
5 min heart rate
10 min heart rate
15 minute heart rate
20 min heart rate
60 beats/min
140 beats/min
160 beats/min
180 beats/min
180 beats/min
Resting breathing rate 8 breaths/min
5 min breathing rate 14 breaths/min
10 min breathing rate 14 breaths per min
15 min breathing rate 18 breaths/min
20 min breathing rate 20 breaths/min
Graph both Kit’s heart rate and breathing results on the same graph using line graphs.
(Use a different colour for each and label.)
Kit’s response to a 20 min run
Heart rate
Breathing rate
(Beats/min)
(Breaths/min)
0
5
10
15
20
Time (minutes)
What happened to the breathing rates when Kit was exercising?
Why did this occur?
What do you think could happen to Kit’s heart rate and breathing rate if he continued to regularly
exercise in this way?
Draw lines to match up the following pairs to explain the long term benefits of training.

The body makes more red blood cells, so…
a) …oxygen is delivered more efficiently.

Arteries get bigger and more elasticised, so…
b) …stroke volume is increased.

More capillaries are formed, so…
c) …it can transport more oxygen.

The heart gets bigger and stronger. So…
d) …its resting level more quickly.

After exercise, heart rate returns to…
e) … blood pressure falls
Fill in the blanks using words from the box below to explain the long term effects of exercise on the
respiratory system.
Biceps, longer, chest cavity, less, rib size, gaseous exchange, capillaries, vital capacity,
oxygen debt, diaphragm, more
The
and intercostal muscles get stronger and increase the
This means you can take in
More
air, increasing
means that
can exercise for
.
.
can take place quicker and you
.
List 4 physiological benefits of endurance training.
1.
2.
3.
4.
Complete the sentences below to give a clear understanding of hypertrophy.
Hypertrophy is when muscles
Tendons also become
List 2 ways in which a trained athlete deals better with lactic acid than an untrained athlete.
1.
2.
Complete the following sentences using words from the box below.
Weights, slow, less, hypertrophy, more, fatigue, speed, fast
sets in, your muscles become tired and don’t
When muscle
function properly. Muscles with lots of
twitch fibres will tire
quickly. Training with
is a good way to
develop muscular endurance.
Draw lines to complete the sentences below.
… will return to resting quicker when
When muscles work hard they need
more oxygen, so …
exercise stops.
An efficient cardiovascular system
will produce a slower heart rate and...
…15-20 minutes within your aerobic
To improve cardiovascular fitness
you must work hard for at least…
…breathing rate and heart rate both
training zone.
increase.
Complete the table below to show the differences between aerobic and anaerobic
respiration. Use the following words / phrases / equations:
Long, lactic acid, Short/explosive, Not Enough, Endurance, Short, Plenty
Glucose + O2
CO2 + H20 + Energy
Glucose
Lactic acid + Energy + O2 + Sweat
Respiration
Amount of
type
O2 supplied
Aerobic
Anaerobic
By-products
Time energy
Events
supplied for
using it
Formula
Physiological Responses to Exercise
Short term / Acute / Immediate
Changes
HR
Explanation
Increases to ensure that more oxygen is delivered to the
working muscles that require additional oxygen so that
the body can work at a higher rate.
SV
Q
Increases to ensure that more oxygen is delivered to the
blood so that more oxygen can be delivered to the body
to sustain a higher work rate. And to remove waste
products of water and lactic acid.
Ventilation
Systolic Blood Pressure
Long term / Chronic Physiological Changes
Changes
Heart Size
Explanation
Heart has adapted through a training programme to
gradually increased workloads.
Resting Heart Rate
As a result of an increase in heart size each beat
now pumps more blood, meaning a lower resting HR
SV
Q
Long term / Chronic Muscular Changes
Changes
Muscle Size
Glycogen Stores
Explanation
When you start to exercise, your body has to make sure that your muscles
get the oxygen they need so they can keep working.
Immediate Responses to Exercise
(Changes during exercise or workout)
 Increase in breathing rate (measured as the no. breaths / min)
 Increase in the volume of air exchanged with each breath
Explanation:
During exercise the working muscles demand more oxygen and the body
needs to expel accumulated lactic acid as carbon dioxide.
To meet these demands our breathing rate will increase significantly and
we will take deeper breaths (i.e. the lungs will inflate more completely
and expel used air more forcefully).
Blood output from the heart is a result of 2 factors:
1. The number of beats per minute (i.e. how fast the heart beats)
2. The volume of blood moved in each beat of the heart (this can vary
depending on the “strength” of each contraction).
During exercise we will see both an:
 Increase in Heart Rate
 Increase in Stroke Volume
Explanation:
During exercise the working muscles demand more oxygen. To provide
this the heart will beat faster and more powerfully.
 “Systolic Blood Pressure” will also increase. This is the pressure in
our arteries when the heart is contracting. The increase is a result of
the change in HR and SV.
 Arterioles widen to stop your blood pressure getting to high
Question: What are the dangers of exercising for someone with
chronic high blood pressure?
 Blood that would usually go to organs like the gut and liver is
diverted to the muscles … by blood vessels either widening
(vasodilation) or constricting (vasoconstriction).
During exercise muscles generate heat.
 To avoid overheating blood is shunted closer to the skin (allows
heat to radiate into environment).
 You also start to sweat, which helps keep you cool
Question: How does sweating keep you cool?
Long Term Responses to Exercise
(Changes as a result of sustained exercise or training programme over a
prolonged period of time).
 Increase in heart size
Explanation: The heart is a muscle (specialized cardiac muscle) and
like any muscle exposed to a training programme, will show an
increase in size (muscle bulk) and strength.
 Increase in stroke volume.
As the heart increases in size it beats more efficiently. Each
contraction expels a greater volume of blood than was possible prior
to the exercise programme.
This leads to a:
 Decrease in Resting Heart Rate, and a
 Decrease in “Diastolic Blood Pressure” and “Systolic B P”.
Blood Pressure = Systolic BP (contraction phase)
Diastolic BP (filling phase)
 Heart rate returns to normal faster
Explanation:
The decrease in Resting HR is a result
Heart Size and
SV.
i.e. the heart can meet the body’s demands with less beats per minute
because each contraction is more efficient.
Changes may also be muscle related:
 Increase in muscle size and strength
 Increase in glycogen stores in working muscle as a result of
increase in size
Mesomorph
3 main body types
Ectomorph
Endomorph
Each of the body types has different characteristics and
one may be suited more to a particular activity or will be
more likely to outperform another person in an activity
than the other body types. It is possible to make some
changes in body type through correct exercises and diet.
 Ectomorphs are typically tall and slender.
 They do not (comparatively) have much muscle and
typically have very little fat.
 Tend to have relatively long bones, so the arms and legs
are comparatively quite long.
 This allows them to reach further, which gives them an
advantage when contesting the ball in sports such as
netball and basketball.
 The longer movements are also an advantage when
running or propelling themselves through water, as they
don’t have to perform as many strides or strokes.
 Longer bones give this body type more reach and a larger
range of movement. Longer bones allow them to gain
more force.
 They are typically suited to endurance sports (they usually
have good aerobic fitness) and sports that do not require a
lot of physical contact.
 Ectomorphs can have better aerobic fitness when
compared to others because they weigh less.
 Endomorphs tend to be shorter and carry larger amounts of
fat compared with Ectomorphs.
 Extra body fat allows them to float better in the water and
provides more insulation from the cold
 Generally bigger than Ectomorphs and the bones are
shorter
 Weight bearing exercises, such as running, can be difficult
 Ideally suited to short duration activities not requiring a lot
of endurance
 Mesomorphs tend to carry a large amount of muscle.
 Typically look athletic (tall , broad shoulders, thin waist,
muscular legs)
 Ideally suited to activities requiring strength and
endurance
 The extra muscle provides power to perform activities
faster and for longer periods of time than other body types.
 Ideal for activities where the body or objects need to be
propelled either over land or water, as well as activities
that require lifting, pulling or pushing, as the extra muscle
can be used to perform this work.
Activity: Body type and sport
Following are nine different sports:
Basketball, Weight lifting, Rugby, Netball, Volleyball, Hockey,
Tennis,
Sumo wrestling
Put each sport under the body type headings Ectomorph,
Mesomorph or Endomorph that they would be ideally suited
to.
Let's begin with the basics of knee anatomy. The knee
joint is made up of three bones and a variety of
ligaments. The knee is formed by the femur (the thigh
bone), the tibia (the shin bone), and the patella (the
kneecap). Several muscles and ligaments control the
motion of the knee and protect it from damage at the
same time. Two ligaments on either side of the knee,
called the medial and lateral collateral ligaments,
stabilize the knee from side-to-side.
The anterior cruciate ligament (ACL) is one of a pair
of ligaments in the center of the knee joint that form a
cross, and this is where the name "cruciate" comes
from. There is both an anterior cruciate ligament
(ACL) and a posterior cruciate ligament (PCL). Both
of these ligaments function to stabilize the knee from
front-to-back during normal and athletic activities.
The ligaments of the knee make sure that the weight
that is transmitted through the knee joint is centered
within the joint minimizing the amount of wear and
tear on the cartilage inside the knee.
The weight-bearing surfaces of your knees are
covered with a layer of cartilage (referred to by
doctors as"articular cartilage"). There are also two
shock absorbers in your knee on either side of the
joint between the cartilage surfaces of the
femur and the tibia. These two structures are
called the medial meniscus and the lateral
meniscus. The menisci are horseshoe-shaped
shock absorbers that help to both center the
knee joint during activity and to minimize the
amount of stress on the articular cartilage. The
combination of the menisci and the surface
cartilage in your knee produces a nearly
frictionless gliding surface. The knee is an
incredible joint. It is strong, flexible, and very
tough.
Movement of the knee
The main muscles that move the knee joint are the quadricep and hamstring muscles. The
quadriceps attaches to the patella, and the patellar tendon connects this muscle to the front of
the tibia. When the quadricep muscles contract the knee extends. In contrast, when the
hamstring muscles contract, they pull the knee into flexion.
Biomechanics
Application: Tennis Serve
How to make a powerful and reliable serve?
- Lift up ball (not throw!!!): the ball location determines
flat/topspin/sidespin
- V shape preparation (Stay at this position for a moment to reserve
energy!!!)
- drop racket head
- cut to the sky
- hit the ball
- pronation of forearm
- land in balance for following strokes
There are three key positions pros use:
(a) trophy position: body is in arc, hitting arm is relaxed
(b) arm twist position: racket head is downward, and keep in right
side
(c) pronation
position: palm
facing out with high
elbow
Tennis Serve
Let us review the 8 key check points below:
Check point #1:
Hold high,and lift straight
Check point #2: V shape preparation,bent knee,bent body
forward,reserve energy
(need to stay at this position for a moment, wait
here, no rush!)
Check point #3: drop the racquet head, parallel to the body, butt to sky,
arm is twicked
Check point #4: swing the racket butt UP, UP, UP, like knife cut into sky,
look at ball
Check point #5: hit the ball, body in balance, free arm/hand does not
drop fast
Check point #6: arm pronation, palm facing outside, not inside down, hold
free hand
Check point #7: finish in foot landing forward, body in good
balance