Knee movement during the gait cycle
THE KNEE:
- FLEXES DURING LOADING RESPONSE (0 to 10 percent)
- EXTENDS DURING MIDSTANCE AND MOST OF TERMINAL STANCE (10 TO 50%)
- FLEXES DEGREES DURING PRESWING AND INITIAL SWING (50 TO 70%)
KNEE FLEXION DURING LOADING RESPONSE
(0 to 10 percent of gait cycle)
- IN THIS CLOSED KINEMATIC CHAIN, THE SCREW-HOME MECHANISM REVERSES:
- FEMUR GLIDES ANTERIORLY ON TIBIA
- ANTERIOR FEMORAL GLIDE BEGINS EARLIER ON MEDIAL CONDYLES, CAUSING EXTERNAL FEMORAL ROTATION
- TIBIA ALSO INTERNALLY ROTATES
- TIBIAL ROTATION IMPARTED BY PELVIC ROTATION
- TIBIAL ROTATION PRODUCES SUBTALAR PRONATION
KNEE EXTENSION DURING MIDSTANCE
- IN THIS CLOSED KINEMATIC CHAIN, THE KNEE EXHIBITS THE "SCREW-HOME" MECHANISM OF TERMINAL ROTATION:
- FEMUR GLIDES POSTERIORLY ON TIBIA
- POSTERIOR FEMORAL GLIDE PERSISTS ON MEDIAL CONDYLES BECAUSE
OF THE LENGTH OF THEIR ARTICULAR SURFACES, CAUSING INTERNAL FEMORAL ROTATION
- TIBIA ALSO ROTATES EXTERNALLY
- TIBIAL ROTATION IMPARTED BY PELVIC ROTATION
- TIBIAL ROTATION PRODUCES SUBTALAR SUPINATION