ch3 (31 57)
TRANSCRIPT
33C H A P T E R
The Biomechanics of Resistance ExerciseThe Biomechanics of Resistance Exercise
Everett Harman
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 ForceMuscle Pulling Force Manifested As a Pushing Force
Muscle Pulling Force Manifested As a Pulling ForceMuscle Pulling Force Manifested As a Pulling Force
Front View of Adult Male Human Skeleton
Front View of Adult Male Human Skeleton
Rear View of Adult Male Human Skeleton
Rear View of Adult Male Human Skeleton
The Vertebral ColumnThe Vertebral Column
Front View of Adult Male Human Skeletal Musculature
Front View of Adult Male Human Skeletal Musculature
Rear View of Adult Male Human Skeletal Musculature
Rear View of Adult Male Human Skeletal Musculature
A LeverA Lever
A First-Class Lever (The Forearm)A First-Class Lever (The Forearm)
A Second-Class Lever (The Foot)A Second-Class Lever (The Foot)
A Third-Class Lever (The Forearm)A Third-Class Lever (The Forearm)
Changes in Mechanical Advantage: Knee Extension and Flexion
Changes in Mechanical Advantage: Knee Extension and Flexion
Changes in Mechanical Advantage: Elbow FlexionChanges in Mechanical Advantage: Elbow Flexion
Changes in Mechanical Advantage: During Weightlifting
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.
Variations in Tendon Insertion Variations in Tendon Insertion
Anatomical Planes of the Human BodyAnatomical Planes of the Human Body
Muscle Fiber Arrangements Muscle Fiber Arrangements
Interaction Between Actin and Myosin Filaments Interaction Between Actin and Myosin Filaments
Resistive Torque: Free WeightResistive Torque: Free Weight
Resistive Torque: Weight StackResistive Torque: Weight Stack
When a weight is held in a static position or
when it is moved at a constant velocity, it exerts
constant resistance, only in the downward
direction. However, upward or lateral
acceleration of the weight requires additional
force.
Supporting the Vertebral Column During Lifting: The Fluid Ball
Supporting the Vertebral Column During Lifting: The Fluid Ball
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.