A research team studied how knee flexor and extensor strength in the residual limb in people with unilateral transtibial amputations impact functional outcome measures, such as walking energetics and performance metrics. Their findings suggest the importance of strength retention of the residual limb knee flexion and extension musculature to improve functional outcomes, they concluded.
Fourteen people with traumatic unilateral transtibial amputations completed metabolic testing at three standardized speeds based on leg length and maximum isokinetic knee flexion and extension strength for the residual and sound limbs. The participants also completed a series of functional outcome tests, including a two-minute walk test, timed stair ascent test, and four-square step test. Walking energetics (metabolic cost, heart rate, and rating of perceived exertion) and performance metrics were compared to the percent deficit of the residual limb to the sound limb’s knee flexion and extension muscle strength.
The data indicated a significant relationship between the percent deficit of knee extension strength and heart rate at a fast walking speed, according to the study. The percent deficit of knee flexion strength related to the rating of perceived exertion at slow and moderate walking speeds. The percent deficit of knee extension strength related to two-minute walk time performance and percent deficit knee flexion strength related to timed stair ascent time.
The study, “Residual limb strength and functional performance measures in individuals with unilateral transtibial amputation,” was published in Gait & Posture.
