# Locomotor Response of Persons with Upper Limb Loss to Treadmill Perturbations

> **NIH VA I21** · JESSE BROWN VA MEDICAL CENTER · 2020 · —

## Abstract

The primary aim of this pilot study is to characterize the proactive and reactive locomotor response of Veterans
with upper limb loss (ULL) to a trip during walking. Our recent VA-funded (RX001388, RX001322) investigations
have suggested that persons with ULL experience a high prevalence of falls and demonstrate postural control
mechanisms that may impair stability. Specifically, nearly half of individuals with ULL at or proximal to the wrist
level experience at least one fall per year and almost a third will experience two or more falls. Further, use of a
prosthesis increases the likelihood of falling by six times, 25% of reported falls resulted from tripping, and nearly
a third of individuals who experience a fall suffer a fall-related injury. Falls can have considerable economic
burden on the VHA and lead to long-term diminished quality of life. Our biomechanical studies suggest that
persons with unilateral ULL display greater postural sway during standing than able-bodied individuals which
increases when wearing a prosthesis, and right/left asymmetry in locomotor stability dynamics that may [increase
the risk of falling toward the impaired limb side and during sound limb side strides]. These findings emphasize
the need for additional research to better understand the mechanisms Veterans with ULL use to control balance
and how [wearing a] prosthesis [affects] these strategies. As our previous research was concerned with steady-
state characterization of postural control, we now plan to build on this work by studying the effects of ULL and
[wearing a] prosthesis on locomotor stability when responding to a trip disturbance during walking. In this context,
locomotor stability is defined as the ability to recover from a perturbation and return to steady-state gait.
We will address the study aims by analyzing trip-induced proactive and reactive locomotor strategy differences
in two study comparisons: 1) Veterans with unilateral transradial level ULL against matched able-bodied controls
[(with and without one arm bound)], and 2) Veterans with unilateral transradial ULL when wearing their customary
prosthesis against not wearing their prosthesis. Controlled, yet unexpected, simulated trips will be delivered
through our custom-built treadmill which permits programmable belt velocity disturbances and allows participants
to continue walking following recovery. We will characterize the proactive and reactive locomotor [stability
mechanisms] through a set of biomechanical (spatiotemporal, angular momentum, arm and trunk kinematics,
recovery step length and time) and electromyography (upper and lower limb muscle activation timing and effort)
variables. Biomechanical variables will be quantified using an optical motion capture system, and
electromyography will be collected with a wireless sensor system. All data will be synchronized with each other
and a time pulse denoting the onset of the treadmill perturbation. We expect that Veterans with ULL will
demon...

## Key facts

- **NIH application ID:** 10013666
- **Project number:** 1I21RX003290-01A1
- **Recipient organization:** JESSE BROWN VA MEDICAL CENTER
- **Principal Investigator:** Matthew J. Major
- **Activity code:** I21 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2020
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2020-07-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10013666

## Citation

> US National Institutes of Health, RePORTER application 10013666, Locomotor Response of Persons with Upper Limb Loss to Treadmill Perturbations (1I21RX003290-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10013666. Licensed CC0.

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