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As a Prosthetist: How Simple Clinical Tests Can Help Predict Fall Risk in Amputees
In everyday practice, we know all too well how devastating falls can be for people with limb loss. Falls aren’t just statistics—they can lead to fractures, head injuries, loss of confidence, prolonged rehabilitation, and reduced community participation. Yet despite this, proactive fall risk screening has often taken a back seat to treating injuries after they occur.
A recent clinical study offers important evidence that simple, clinic-friendly assessments can help us identify amputees at higher risk of falling before a fall happens. These tests don’t require advanced technology or lengthy protocols—just careful observation, timing, and a basic understanding of gait and balance.
Why Level of Amputation Matters
One key insight from this research is that fall risk isn’t uniform across all amputees. Below-knee (transtibial) and above-knee (transfemoral) prosthesis users face different challenges, so the tests that predict risk best also differ by amputation level.
Practical Clinical Tests to Use
1. Four Square Step Test (FSST) – For Below-Knee Users
In this test, patients step quickly forward, backward, and sideways over low obstacles arranged in a square. It’s a functional balance and agility drill that simulates common daily mobility demands. In the study’s transtibial group, those who took 12.83 seconds or longer to complete the FSST were significantly more likely to fall over the next six months compared to faster performers.
As prosthetists, we can incorporate the FSST easily during routine gait and balance evaluations—timing it, observing movement quality, and using it as a flag for targeted interventions.
2. Walking Speed – A Vital Sign for Mobility
Walking speed—measured over a consistent distance at a patient’s comfortable pace—is a powerful indicator of functional mobility. In below-knee amputees, slower gait speed (less than 1.28 m/s, or about 2.9 mph) was associated with higher fall risk. Interestingly, this threshold is faster than standard fall risk cut-offs used for older, non-amputee adults, suggesting prosthetic gait demands more dynamic stability.
Clinically, regular gait speed checks can help us track longitudinal change, assess interventions, and plan rehabilitation goals.
3. Timed Up and Go (TUG) – Especially Useful for Above-Knee Users
The TUG involves standing from a chair, walking a short distance, turning around, and sitting down again. It combines transitional movements and dynamic balance measures. For transfemoral prosthesis users, those who took 9.44 seconds or longer were more likely to fall in the following six months. Though the above-knee sample was small, the pattern aligns with the higher balance demands and gait asymmetry intrinsic to knee prostheses.
In practice, the TUG is quick, familiar to most rehabilitation teams, and provides meaningful information about a patient’s dynamic transitional stability.
What This Means for Clinical Care
These findings reinforce something that experienced prosthetists already observe: fall risk is multifactorial and needs to be measured proactively, not assumed retrospectively. Using objective, simple tests in the clinic:
- Helps us identify individuals who may benefit from balance training, strength conditioning, or environmental modifications.
- Allows targeted prosthetic component adjustments—for example, optimizing foot and knee choices, alignment, and suspension to improve confidence and stability.
- Provides a measurable way to monitor progress over time as patients adapt to new prostheses.
It’s also important to recognize that self-reported balance confidence doesn’t always match actual fall risk—some patients who appear confident may nonetheless be at high risk based on performance tests.
Putting It Into Practice
These tests are quick, require minimal equipment, and can be integrated into standard evaluations:
- FSST: balance and agility
- Walking Speed: functional gait assessment
- TUG: transitional mobility and overall balance
By routinely incorporating these assessments and tracking results longitudinally, prosthetists can play a more proactive role in fall prevention—enhancing safety, independence, and quality of life for the people we serve.
