Physiological risk factors for falls in older people with lower limb arthritis.

OBJECTIVE: To investigate physiological risk factors for falls in people with self-reported lower limb arthritis.

METHODS: Six hundred eighty-four community-dwelling men and women aged 75-98 years (mean 80.0, SD 4.4), categorized with and without lower limb arthritis, underwent quantitative tests of strength, peripheral sensation, vision, reaction time, balance, and pain. A 12-month history of falls was also obtained.

RESULTS: Subjects with self-reported lower extremity arthritis performed significantly worse in tests of knee and ankle muscular strength, lower limb proprioception, postural sway, and leaning balance than subjects without lower extremity arthritis, while being comparable in vision, tactile sensitivity, and reaction time. This pattern of specific impairments was also evident when group results for the arthritis subjects were compared with community normative values and presented as a physiological profile. The arthritis group suffered significantly more falls [relative risk (RR) 1.22, 95% CI 1.03-1.46] and injurious falls (RR 1.27, 95% CI 1.01-1.60) in the previous 12 months than the nonarthritis group. Within the arthritis group, reduced knee extension strength and increased sway were identified as significant predictors of falls.

CONCLUSION: Older people with lower limb arthritis are at increased risk of falling due to deficits in neuromuscular systems. A physiological falls-risk profile based on mean test scores for the arthritis group highlights deficits in muscular strength, knee proprioception, and standing balance, indicating the need for targeted falls prevention interventions for this population.