Persistent pain is associated with poorer balance and gait performance for people with Chronic Obstructive Pulmonary Disease

Background: People with COPD fall due to balance and gait impairments, and frequently report pain. The influence of pain on balance and gait in people with COPD is unknown. We aimed to compare balance and gait in people with COPD with and without persistent pain and explore factors associated with poor balance and gait. Methods: 43 participants’ characteristics and pulmonary rehabilitation outcomes were recorded. Participants were assigned to two groups, those with persistent pain (pain lasting ≥3months) (n = 25) and those without (n = 18) for analysis. Between-group differences were calculated for pain (BPI-SF), balance (BESTest, BBS), gait (GAITrite), isokinetic hip, knee and ankle strength (MVC), lower limb muscle endurance (30 s STS), physical activity (PASE) and Maximal Inspiratory Pressure (Pimax). Associations between neuromuscular factors and balance/gait outcomes were investigated. Results: BESTest and BBS scores were 14.0 % (95 % CI: 7.4–20.6) and 3.0 (95 % CI: 0.7–5.3) lower, for the persistent pain group. Mean gait speed was slower for the pain group (0.99 m/s vs 1.18 m/s, 95 %CI for difference: 0.03–0.35 m/s, group main effect: p = 0.02). The mean reduction in dual-task vs single-task gait speed was greater in the pain group (0.12 m/s vs 0.05 m/s, interaction effect: p = 0.045). Lower BESTest scores were associated with poorer muscle endurance (r = 0.650), pain severity (r = −0.584), and weaker hip abductors (r = 0.370) and ankle plantar-flexors (r = 0.438). No associations were apparent for gait speed. Conclusion: People with COPD plus pain have worse balance and slower gait speed, especially under dual-task conditions. Pain severity, muscle endurance and hip and ankle strength are associated with balance performance.