Biomechanical Analysis & Movement Flashcards

What is the 'length-tension relationship' in muscle physiology?

Answer: A muscle produces peak force at an optimal resting length where actin-myosin overlap is ideal

The length-tension relationship describes that a muscle generates peak force at its optimal resting length, where actin and myosin filaments have the greatest overlap.

During the push-off phase of gait, which muscle group is the primary contributor to propulsion?

Answer: Plantar flexors (gastrocnemius/soleus)

The plantar flexors, primarily the gastrocnemius and soleus, generate the propulsive force during the push-off (terminal stance to pre-swing) phase of gait.

Synergistic dominance occurs when which of the following happens?

Answer: Synergist muscles compensate for a weakened or inhibited prime mover

Synergistic dominance occurs when synergist muscles overwork to compensate for an inhibited or weak prime mover, leading to altered movement patterns.

In a postural assessment, a client with forward head posture typically exhibits which compensatory pattern at the cervical spine?

Answer: Cervical flexion with upper cervical extension

Forward head posture involves lower cervical flexion combined with upper cervical (atlanto-occipital) extension, causing the chin to jut forward.

What does 'ground reaction force' (GRF) represent in gait biomechanics?

Answer: The equal and opposite force the ground exerts on the body in response to the body's force

Ground reaction force is the equal and opposite force exerted by the ground on the body in response to the body's applied force, per Newton's Third Law.

Which muscle is considered the primary stabilizer of the lumbar spine during functional movements due to its attachment to the thoracolumbar fascia?

Answer: Transverse abdominis

The transverse abdominis (TVA) is the deepest abdominal muscle and provides segmental lumbar stability through its attachment to the thoracolumbar fascia.

Which of the following best describes 'arthrokinematics'?

Answer: The motion occurring between joint surfaces (roll, spin, glide)

Arthrokinematics refers to the small accessory motions (rolling, spinning, gliding) that occur between the articular surfaces of a joint during movement.