Anatomy, Biomechanics, & Gait Analysis Flashcards

The 'calcaneus gait' pattern, characterized by excessive heel contact without a push-off, is most commonly caused by:

Answer: Weak plantar flexors or a prosthetic foot set in excessive dorsiflexion

Calcaneus gait results from inadequate plantar flexor strength or a prosthetic foot aligned with too much dorsiflexion, eliminating effective push-off.

Which structure is the primary weight-bearing surface of the ischial tuberosity in a traditional ischial containment transfemoral socket?

Answer: The ischial seat shelf integrated into the medial-posterior wall

Ischial containment sockets use a specifically contoured ischial seat shelf on the medial-posterior wall to capture and load the ischial tuberosity.

During mid-stance, the center of mass reaches its highest point in the vertical displacement sinusoidal curve. This is an example of which biomechanical determinant of gait?

Answer: Vertical displacement

Vertical displacement of the center of mass follows a sinusoidal pattern, peaking during single limb support (mid-stance) and reaching its lowest at double support.

The sciatic nerve, if damaged proximal to the knee, would most directly impair function of which muscle group critical to prosthetic rehabilitation?

Answer: Hamstrings and all muscles below the knee

The sciatic nerve innervates the hamstrings and all muscles of the lower leg (via its tibial and common peroneal branches), profoundly affecting residual limb control.

Which parameter of gait typically DECREASES as walking speed increases?

Answer: Double support time

Double support time decreases as walking speed increases and disappears entirely during running, when both feet are never simultaneously on the ground.

A transtibial amputee exhibits 'whip' motion of the prosthetic foot during swing phase. The most likely cause is:

Answer: Rotational malalignment of the prosthetic foot relative to the socket

Whip motion (medial or lateral) during swing is caused by rotational malalignment between the socket and prosthetic foot, creating inward or outward flinging.

Which joint motion occurs in the transverse plane during normal gait as the pelvis rotates forward with each step?

Answer: Hip internal and external rotation

Pelvic rotation in the transverse plane requires alternating internal and external rotation at the hip joints to maintain smooth forward progression.