Biomechanics & Gait Analysis Flashcards

During normal gait, which muscle group is primarily responsible for controlling the rate of foot lowering (foot slap prevention) immediately after heel strike?

Answer: Tibialis anterior

The tibialis anterior eccentrically contracts after heel strike to lower the foot to the ground in a controlled manner, preventing foot slap.

What is the term for the excessive outward rotation of the foot during ambulation, often compensating for limited hip internal rotation?

Answer: Out-toeing

Out-toeing refers to external rotation of the foot during gait, commonly seen as a compensatory mechanism for reduced hip internal rotation range of motion.

The 'double support phase' of normal gait refers to the period when:

Answer: Both feet are in contact with the ground simultaneously

Double support occurs twice per gait cycle when both feet are simultaneously in contact with the ground, comprising approximately 20% of the gait cycle at normal walking speeds.

A patient with a spastic equinovarus foot in cerebral palsy would most likely exhibit which gait deviation during swing phase?

Answer: All of the above are common compensations

Spastic equinovarus causes foot clearance problems during swing, leading patients to compensate with steppage gait, vaulting on the stance limb, or circumduction of the affected limb.

Which parameter of gait is most directly measured by counting the number of steps taken per unit of time?

Answer: Cadence

Cadence is defined as the number of steps taken per minute and is directly measured by counting steps over a given time interval.

In the biomechanical model of the foot, the 'subtalar joint neutral position' is clinically important because it represents:

Answer: The position where the foot is neither pronated nor supinated

Subtalar neutral is defined as the position where the subtalar joint is neither pronated nor supinated, serving as a reference point for orthotic casting and assessment.

Which component of the ground reaction force vector is responsible for the 'anterior shear' force experienced at the knee during the loading response?

Answer: Anterior-posterior (horizontal) component

The anterior-posterior horizontal component of the GRF creates an anterior shear at the knee during loading response, contributing to knee joint stress and ACL loading.