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Chapter 9 Running, Jumping, Throwing, Kicking & Lifting Running • Walking to Running – 5 m/s or 4.5 mph • Complex interaction of body movements • Walking: Double & Single Support • Running; Single Support & Flight phase As speed increases • First increases to stride length – Anatomic limitors • Then all further increases in velocity due to stride rate increases As speed increases • 60-40 Walk • Run – 50-50 – 30-70 – 20-80 Muscle Activity • End Swing Phase – Glut-max: Ecc Slow Hip Flexion – Hamstrings: Ecc Slow Knee Ext – Tibialis-Ant conc dorsiflex-ankle • Early Stance – Glut-max, quad, gastro -> extensions – Tibialis-Ant (isometricaly ?) stabilize • Late Stance – Plantar Flexors give push • Through out EMG increases in magnitute – Absolute Time (decrease) – Relative (increase of % cycle) Life Span perspective …2+… • Muscle strength and flight phase – Stride Length, ROM, Trunk Rotation • Levels – – – – 1 Arms Assist Feet flat – swing leg abducted 2 Arms swing trunk rotation Knee Flexion speed increase 3 Arm swing increase Heel- sagittal toe-off 4 Arm independent trunk opposition – Older Adults – Acute vs Chronic Injuries Jumping • Jumping – Land on both feet • Hopping – Take off & Land same foot • Leaping – Take off from one foot land on another Basic Jumps • Counter-movement Stretch-Shorten-Cycle (SSC) • Squat • Hip-Knee – Extensors – Arms 10% • End of Flight Phase – Anticipatory Life-Span …Jumping • Children – 2-2, 1-2, 2-1 … also forward – Over objects • SSC Jumps Jumping Injuries • Knee Extensor Mechanism (KEM) – Quads-patellofemoral-tendon • Patellar – Maltracking – Tendinitis – Chondromalacia (degeneration) • Quads – tendinitis Throwing • Upper Extremity launch a handheld object through air • Projectile (object) and Ballistics (study) • Overarm-underarm • Push – Pull? • Trajectory – Apex • Speed -Angle -Height Throws … Throwing Phases • Preparatory – Favorable position – ROM – larger inside – SSC – Length Tension – Elastic Energy • Action – Proximal to Distal • Recovery – Slow down decelerate Windup and Cocking EMG – Muscle activity Life Span …Throwing • Arm action (back-forward) • Trunk Hip – Trunk – Hip flexion – Pelvic – trunk rotation – Uncoupling • Ipsilateral movement • Backswing • Force production ROM Throwing Injuries • Impingement Syndrome – Suprahumeral structure (supraspinatus, subacromial bursae) against acromion & cocacoacromial ligament • Medial Epicondylitis – Medial epicondylitis (ME) is an overuse injury affecting the flexor-pronator muscle origin at the anterior medial epicondyle of the humerus. ME is often discussed in conjunction with lateral epicondylitis (LE), which occurs much more frequently. – ME:LE = 1:5 Kicking • Proximal to distal • Impact – non-weight bearing • Phases – Approach – Momentum Build Up – Pre-impact – • Non-kicking leg support – • Thigh Swing -- thigh slow down before impact – Impact .1 seconds or less – Follow Through • Hip Muscles whiplike sequencing – Knee extensors minimal? (force-velocity curve) Life-Span • ROM • Push to impact • Foot Placement • Injuries – Knee – Ankle Lifting Techniques • Squat Stoop • National Institute of Occupational Safetty and Health (NIOSH) http://www.cdc.gov/NIOSH/ • Keep load close to body • Use legs • Leg Extensors vs Trunk Extensors • Anticipatory Postural Adjustments (APA) Injury related • Children Older Adults – Muscle strength dependence • Lifting and Back disorders – $$ – 80% – Reduce loads --- increase strength • Safety Guidelines Safety Guidelines • Design work tasks that facilitate variety (i.e., don’t do too much of any single thing). • Avoid a fully flexed or bent spine and rotated trunk when lifting. • Select a posture to minimize the reaction torque on the low back by keeping the external load near the body. • Minimize the weight being lifted. • Do not immediately perform strenuous exertions after periods of prolonged flexion. • Avoid lifting or spine bending after rising from bed. • Prestress and stabilize the spine during light lifting tasks. • Avoid twisting while generating high twisting torques. • Use momentum when exerting force to lower spinal loads. • Avoid prolonged sitting. • Adopt appropriate rest strategies. • Maintain a reasonable level of physical fitness.