LAUSR

Case description: A 30-year-old person with a unilateral transtibial amputation (TTAmp) was assessed performing an Olympic-style back squat with an energy storage and return prosthetic foot. Objective: Determine joint-level movement strategies of an individual with TTAmp while performing an Olympic-style back squat. Study design: Case study design. Treatment: Back squat mechanics are evaluated in an individual with TTAmp by comparing the contribution of the ankle, knee, and hip joint to total positive and negative amputated and sound limb work. Outcomes: The hip joint was the greatest contributor to total positive limb work compared with the knee and ankle, respectively, in the amputated (55.0% hip vs. 30.8% knee, P < 0.001; vs. 14.2% ankle, P = 0.001) and sound limbs (52.2% hip vs. 38.9% knee, P < 0.001; vs. 8.9% ankle, P < 0.001). The hip joint was the greatest contributor to total negative limb work compared with the ankle in both the amputated (51.0% hip vs. 15.9% ankle, P < 0.001) and sound limbs (47.3% hip vs. 10.0% ankle, P < 0.001) and the knee in the amputated limb (51.0% hip vs. 32.5% knee, P < 0.001). Ankle joint power demonstrated an atypical bimodal negative/positive/negative/positive pattern. Conclusion: The individual with TTAmp used a hip-dominant joint strategy in both the amputated and sound limbs while demonstrating more potential to optimize the prosthetic foot’s energy storage and return capabilities when performing a back squat.