Chronic pain slows foot reaction time in seniors

Elderly adults with chronic pain have slower foot reaction times, which in turn may contribute to higher fall risks, a new study has found.

Researchers conducted a cross-sectional analysis of 307 adults aged ≥71 years, in whom pain severity, interference, and location were assessed using the Brief Pain Inventory and a joint pain questionnaire. The Simple (SRT) and Choice (CRT) Reaction Time tests were performed to measure foot reaction times.

The average SRT was 0.245±0.057 seconds, while CRT was 0.323±0.08 seconds. Participants who were older had significantly slower foot reaction times in both measures (p=0.02 for both); no such effects of sex or race were observed. Weaker cognitive performance was likewise linked to impaired SRT and CRT, while reporting ≥2 falls in the past year was associated with SRT alone (p=0.04).

Generalized linear models, adjusted for baseline demographics and the Trail Making Test-part A, found that pain severity (p=0.022) was a significant predictor of slower SRT. Adjusting only for demography additionally revealed a significant link between pain interference and slower SRT (p=0.041).

Pain had stronger effects on CRT. In the adjusted models, pain severity (p=0.012), lower-body pain (p=0.023), and knee pain (p=0.002) were all correlated with slower CRT.

“Adjusting for other fall risk factors, potentially on the pathway from pain to slowed reaction time, diminished the association in all but the knee pain relation to CRT,” the researchers said.

“A better understanding of the pathway could lead to interventions that potentially could improve foot reaction time among older adults living with chronic pain as part of a physical therapy or exercise-based intervention to reduce fall risk,” they added.