# Effects of a custom forelimb prosthesis on weight distribution, stability, and gait in a canine amputee: A multi-method approach

## TL;DR

A custom prosthesis improved weight distribution and gait in a dog with a forelimb amputation, though not to the level of a healthy dog.

## Contribution

This study demonstrates functional benefits of a custom prosthesis for canine forelimb amputees using a multi-method approach.

## Key findings

- The prosthesis increased total forelimb load from 49% to 56% and reduced contralateral limb load.
- Gait symmetry and efficiency improved with the prosthesis, though not reaching the levels of a healthy dog.
- Stability improved as indicated by a significant reduction in sway path length.

## Abstract

We aimed to evaluate whether the use of a custom prosthesis improves static stability and gait symmetry in a dog with a forelimb amputation. This study involved two therapy dogs owned by the same individual, both mixed breeds with similar physical characteristics. Dog with amputation had a full forelimb amputation and had been successfully using a prosthesis since 2022. Healthy dog served as a control in three different assessment methods evaluating prosthetic effectiveness. For static measurements, a four-scale method and a force plate were used; dynamic data were collected using a pressure-sensor mat. Dog with amputation distributed 21 % of its body weight onto the prosthesis, reducing the load on the contralateral limb from 49 % to 35 %. The total forelimb load increased from 49 % to 56 % with the prosthesis. Stabilometric analysis indicated improved stability with the prosthesis: significant reduction in sway path length, while changes in directional sway components and sway area were not statistically conclusive. Sensor-mat measurements on GAITRite showed that forelimb amputation substantially reduced step length (21.1 cm) and stride length (42.4 cm) on the amputated side, and increased traversal time to 2.4 s, reflecting pronounced gait asymmetry and impaired limb function. The use of a prosthesis improved step length (35.0 and 30.1 cm) and stride length (64.1 and 63.0 cm), and decreased traversal time to 2.2 s, indicating enhanced gait efficiency, although values did not fully reach those of the healthy dog (step length 46.8/44.6 cm; stride length 93.5/87.7 cm; time 1.5 s). These results demonstrate the functional benefits of prosthetic use in canine forelimb amputation.