The six determinants of gait are a set of biomechanical factors that contribute to the efficiency and effectiveness of human walking. These determinants help optimize stability, minimize energy expenditure, and facilitate forward progression during locomotion.
The six determinants are considered as:
- Pelvic rotation: The pelvis rotates in the transverse plane during gait to minimize vertical displacement of the body’s center of mass, reducing energy expenditure. The rotation allows for counter-rotation of the shoulders, which helps maintain balance.
- Pelvic tilt: The pelvis tilts downward on the side of the swinging leg and upward on the side of the stance leg. This movement helps to lengthen the stride of the swinging leg and creates an adequate step length.
- Knee flexion: During the swing phase, the knee of the swinging leg flexes to allow clearance of the foot from the ground. Adequate knee flexion ensures that the toe doesn’t catch on the ground, preventing trips or falls.
- Ankle motion: The ankle joint has a specific pattern of motion during the gait cycle. During the stance phase, the ankle initially dorsiflexes to absorb shock as the foot makes contact with the ground, and then plantarflexes to push off and propel the body forward during the toe-off phase.
- Foot progression angle: The foot progression angle refers to the angle formed between the long axis of the foot and the direction of walking. Normally, the foot points slightly outward (approximately 7-10 degrees) to provide a stable base of support and maintain balance.
- Lateral pelvic displacement: During the stance phase, the pelvis moves horizontally to the side of the stance leg. This lateral pelvic displacement helps to shift the body’s center of mass over the stance leg, providing stability and balance.
These determinants work together to ensure efficient and coordinated movement during walking. Deviations or abnormalities in any of these determinants can affect gait patterns and may be indicative of certain gait abnormalities or impairments. However, these six determinants are not without controversy.