# Muscle forces and the demands of turning while walking

## TL;DR

This study compares muscle forces during turning and straight walking, finding differences in timing and magnitude for hip and ankle stabilizing muscles.

## Contribution

The study identifies novel muscle force patterns during turning movements compared to straight walking using a musculoskeletal model and statistical parameter mapping.

## Key findings

- Muscle forces stabilizing the hip and ankle differ in timing during turning compared to straight walking.
- The magnitude of muscle forces changes across different turning conditions.
- Statistical parameter mapping reveals significant differences in force patterns between turning and straight walking.

## Abstract

Turning is a ubiquitous feature of human locomotion and like straight path walking, requires muscular force both to propel the individual forward and to stabilize the trunk over the stance limb. The purpose of this study is to identify muscle force patterns while making a turn and compare them to those of straight path walking. Kinematic and kinetic data were collected from 10 adults who walked unshod at their self-selected normal velocity in four conditions: straight line, 45° and 90° turns with a sidestep, and a 45° crossover event. A musculoskeletal model was used to calculate muscle forces in the pelvis and lower limb. Statistical parameter mapping (SPM) was used to determine whether the muscle force patterns of the three turning conditions were different from walking in a straight path. We find that, overall, the muscles that stabilize the hip and ankle during walking demonstrate differences in timing and magnitude of their force patterns across all turning conditions.

Summary: Force patterns of the muscles that stabilize the hip and ankle show differences in timing and magnitude compared to force patterns of straight-path walking.