# Grip strength but not stair climb power is associated with injurious falls in middle-aged and older women: The Study of Women’s Health Across the Nation (SWAN)

## TL;DR

Higher grip strength in older women is linked to fewer falls and fewer injurious falls, suggesting muscle strength could be a target for fall prevention.

## Contribution

This study identifies grip strength as a specific modifiable factor associated with fall risk in older women.

## Key findings

- Higher grip strength was associated with 18% lower odds of non-injurious falls.
- Higher grip strength was associated with 19% lower odds of injurious falls.
- Stair climb power was not associated with either non-injurious or injurious falls.

## Abstract

We examined both muscle strength and power in relation to non-injurious and injurious falls in older women. Higher grip strength, but not stair climb power, was associated with lower odds of both fall outcomes. Findings highlight muscle strength as a potential target for fall prevention strategies in older women.

Falls are the leading cause of injury and injury death in older women, with an increase in fall prevalence during midlife. While muscle strength and power may be modifiable risk factors for falls, associations of both muscle strength and power with injurious falls have not been investigated together in a study of community-dwelling middle-aged and older women.

In the Study of Women’s Health Across the Nation (SWAN), muscle function and falls were measured in 2015–2017 and 2021–2023 (6.6 ± 0.3 years follow-up). Muscle function tests included grip strength (kg/weight(kg)) and stair climb power (W/weight(kg)). Self-reported falls in the past year were categorized as no falls, non-injurious falls, or injurious falls (fractured bone, hit/injured head, sprain/strain, bruises, bleeding, other). Generalized estimating equations were used to model associations between time-varying muscle function measures and fall outcomes adjusted for demographics, body size, lifestyle factors, and multimorbidities.

Among 1710 women (age 65.0 ± 2.7 years), 28% reported injurious falls and 16% reported non-injurious falls during the study period. Average declines were -1.37%/year for stair climb power and -0.90%/year for grip strength. In final models, a 1 standard deviation (0.10 kg/kg) higher grip strength was associated with 18% lower odds of non-injurious falls (OR = 0.82, 95% CI 0.69–0.98) and 19% lower odds of injurious falls (OR = 0.81, 95% CI 0.70–0.94). Stair climb power was not associated with either fall outcome.

Muscle strength may be a potential target for musculoskeletal interventions to reduce fall and fall injury risk in older women.