3 C H A P T E R The Biomechanics of Resistance Exercise

Chapter Outline The musculoskeletal system Human strength and power Sources of resistance to muscle contraction Joint biomechanics: concerns in lifting Movement analysis and exercise prescription

Muscle Pulling Force Manifested As a Pushing Force

Muscle Pulling Force Manifested As a Pulling Force

A Lever

A First-Class Lever (The Tricep)

A Second-Class Lever (The Foot)

A Third-Class Lever (The Forearm)

Changes in Mechanical Advantage: Knee Extension and Flexion

Changes in Mechanical Advantage: Elbow Flexion

Changes in Mechanical Advantage: During Weightlifting

 Most of the skeletal muscles operate at a considerable mechanical disadvantage. Thus, during sports and other physical activities, forces in the muscles and tendons are much higher than those exerted by the hands or feet on external objects or the ground.

Supporting the Vertebral Column During Lifting: The Fluid Ball Read p.49

 Resistance training is quite safe compared with other sports and fitness activities. Prudence can keep injuries to a minimum. Basic safety principles include good lifting form, appropriate resistance, accommodation to injuries, balance, and variety.

 Specificity is a major consideration when designing an exercise program to improve performance in a particular sport activity. The sport movement must be analyzed qualitatively or quantitatively to determine the specific joint movements that contribute to the whole-body movement. Exercises that use similar joint movements are then emphasized in the resistance training program.

Front View of Adult Male Human Skeleton

Rear View of Adult Male Human Skeleton

The Vertebral Column

Front View of Adult Male Human Skeletal Musculature

Rear View of Adult Male Human Skeletal Musculature

 Action/ Origin/Insertion of Selected Muscles Lower Body Sartorius Adductors Biceps Femoris Gracilis Semimembranosus Gluteus Maximus Semitendinosus Gluteus Medius Gastrocnemius Rectus Femoris Soleus Tibialis Anterior http://www.rad.washington.edu/atlas2/

 Action/ Origin/Insertion of Selected Muscles Lower Body Deltoid Rhomboids (Anterior/Middle/Posterior) Pec Major Trapezius Biceps Latissimus Dorsi Brachialis Brachioradialis Rotator Cuff Supraspinatus Infraspinatus Teres Minor Subscapularis http://www.rad.washington.edu/atlas2/

 Terms ROM Plane Anterior vs Posterior Flexion S Lateral vs Medial Extension S Proximal vs Distal AB/AD F Superior vs Inferior IR/ER T Circumduction S/F/T Lateral Bending F

Anatomical Planes of the Human Body