Powered Prosthetic Feet Osteoarthritis Risk: What This New Study Shows
Intro
Powered prosthetic feet osteoarthritis risk is an important topic for people with a below-knee (transtibial) amputation and their care teams. Many hope that powered ankles will “protect” the intact knee by improving push-off and smoothing out gait. A new study in the Journal of Biomechanics looked closely at how different prosthetic feet affect loading on the intact (contralateral) knee during walking.
Researchers compared three types of feet in 29 adults with unilateral transtibial limb loss:
- Powered feet (POW)
- Energy-storing and returning feet (ESR)
- Articulating ESR feet (ART), often with hydraulic or pivoting ankles
Their goal: see whether powered feet actually reduce forces linked to knee osteoarthritis compared with other commonly prescribed feet.
Key Findings
- Powered vs ESR feet: similar knee loads
- Powered feet produced more push-off power, but this did not translate into lower forces on the intact knee.
- Vertical ground reaction forces (vGRF), knee adduction moments (KAM), and tibiofemoral contact forces (TCF) were similar between powered and ESR feet across walking speeds.
- Articulating feet showed the highest knee loading
- ART feet were associated with the largest contralateral knee loads, including:
- Higher first peak vGRF
- Higher KAM loading rates
- Higher peak tibiofemoral contact forces
- Lower prosthetic push-off power in ART feet seemed to explain some of this increased loading.
- ART feet were associated with the largest contralateral knee loads, including:
- Walking faster increases knee loading for all feet
- Regardless of foot type, higher walking speeds led to increased loading on the intact knee.
- Knee loads still higher than in non-amputees
- Even with modern powered feet, knee loading measures in participants with transtibial limb loss remained higher than values reported in people without amputations at similar walking speeds.
Why It Matters (for Patients and Providers)
- Foot type alone may not prevent osteoarthritis
- This study suggests that simply switching to a powered prosthetic foot may not be enough to reduce biomechanical knee osteoarthritis risk on the intact side.
- ESR feet performed similarly to powered feet in terms of knee loading, despite lower push-off power.
- Articulating/hydraulic feet: possible trade-offs
- Articulating ESR feet may improve comfort or residual limb loading, but they may also increase forces through the intact knee.
- Clinicians may need to balance socket comfort, residual limb health, and contralateral knee protection when choosing these devices.
- Think beyond components
- Since powered prosthetic feet osteoarthritis risk remains elevated, a knee-preservation strategy should include:
- Gait training and strengthening (hips, quadriceps, trunk)
- Weight management and activity pacing
- Close monitoring for knee pain or early osteoarthritis signs
- Foot and alignment choices tailored to the individual’s goals, gait pattern, and comorbidities
- Since powered prosthetic feet osteoarthritis risk remains elevated, a knee-preservation strategy should include:
For prosthetists and rehab teams, this paper reinforces that component choice is important but not magic—comprehensive rehab and long-term follow-up remain critical.
Conclusion
This large, functionally diverse study of adults with unilateral transtibial limb loss found that modern powered prosthetic feet did not reduce intact-knee loads compared with conventional ESR feet during level walking. Articulating ESR feet produced the highest contralateral knee loads, suggesting a potential trade-off between residual limb comfort and intact knee loading.
For patients, the key message is that protecting the intact knee likely requires a combination of the right prosthetic foot, proper alignment, targeted strengthening, and smart activity levels—not just upgrading to a powered ankle.
If you have a transtibial amputation and are wondering which prosthetic foot is best for your long-term knee health, talk with your prosthetist and rehab team about your goals, gait pattern, and any knee discomfort you may already feel.
Reference
Golyski PR, Hendershot BD, Chomack JM, Gladish JR, Herlihy DV, Maikos JT.
Powered prosthetic feet do not decrease contralateral knee loads relative to energy storing and returning feet during walking in a functionally diverse cohort of individuals with unilateral transtibial limb loss. Journal of Biomechanics. 2026;194:113031. doi:10.1016/j.jbiomech.2025.113031