Biomechanics & Gait Analysis Flashcards

During normal gait, the stance phase comprises approximately what percentage of the gait cycle?

Answer: 60%

Stance phase normally accounts for approximately 60% of the gait cycle, while swing phase accounts for the remaining 40%.

Which of the following best describes heel strike in normal gait?

Answer: The posterior lateral heel contacts the ground first

During normal heel strike, the posterior lateral aspect of the heel contacts the ground first, initiating the loading response.

What is the normal range of subtalar joint motion required for efficient gait?

Answer: 6–10 degrees

Approximately 6–10 degrees of subtalar joint motion (combined inversion and eversion) is required for efficient shock absorption and propulsion during gait.

Which muscle is the primary decelerator of tibial advancement during the loading response of gait?

Answer: Tibialis anterior

The tibialis anterior eccentrically contracts during the loading response to control plantar flexion after heel strike, decelerating tibial advancement.

The windlass mechanism during push-off primarily involves which structure?

Answer: Plantar fascia

The windlass mechanism involves the plantar fascia tightening as the toes dorsiflex during push-off, raising the longitudinal arch and supinating the foot to create a rigid lever for propulsion.

What is the Q-angle, and which finding raises concern in orthotic assessment?

Answer: Angle between the quadriceps force vector and the patellar tendon; values above 20° in females are abnormal

The Q-angle is formed between the quadriceps pull line and the patellar tendon; values exceeding 20° in females (and 15° in males) indicate increased lateral patellar stress and potential biomechanical dysfunction.

During midstance, what is the primary function of the tibialis posterior muscle?

Answer: Inverting the subtalar joint and supporting the medial longitudinal arch

During midstance, the tibialis posterior eccentrically contracts to control pronation by inverting the subtalar joint and supporting the medial longitudinal arch.