Turning Time and Velocity Are Associated with Balance Confidence and Self-Perceived Walking Limitation in Multiple Sclerosis
Persons with multiple sclerosis (pwMS) frequently report difficulty turning and transitioning between seated and standing positions. Rehab strategies can target these impairments to improve mobility and independence, and prevent falls and injury.
PwMS with greater self-perceived impairments of balance and walking demonstrate more impairment in postural transitions that incorporate turning.
50 persons with MS (pwMS) (age: 47.3 ± 10.3; 40 female, 10 male) and mild to moderate clinical disability (EDSS: 0-4, median = 2.5) completed 3 trials of a 7 meter Timed Up and Go (TUG) test while wearing opal body-worn motion sensors (APDM®, Portland, Oregon, USA). The TUG is a standardized clinical scale of functional mobility that includes turning and postural transitions. Mobility Lab software (APDM®, Portland, Oregon, USA) measured TUG total duration and postural transition parameters during sit-to-stand, turning, and turn-to-sit. The Activities-specific Balance Confidence Scale (ABC) and 12-item Multiple Sclerosis Walking Scale (MSWS-12) assessed balance confidence and self-perceived limitations in walking. Spearman rho correlations assessed associations between postural transition parameters to the ABC and MSWS-12. Mann-Whitney U tests compared TUG parameters between mild (EDSS 0=2, n = 23) vs. moderate disability (EDSS 2.5-4, n = 27) subgroups.
Balance confidence on the ABC decreased with longer turning duration, turn-to-sit duration (r = -0.49, r = -0.51, both p < 0.001), and lower peak turning velocity and peak turn-to-sit velocity (r = 0.49, r = 0.58, both p < 0.001). Greater self-perceived walking limitation on the MSWS-12 was associated with longer turning duration (r = 0.36, p = 0.01) longer turn-to-sit duration (r = 0.53, p < 0.001), lower turning velocity (r = -0.38, p < 0.01) and lower turn-to-sit velocity (r = -0.59, p < 0.001). Stand-to-sit duration and peak sit-to-stand velocity were not significantly (p > 0.05) associated with the balance confidence (ABC: |r| < 0.19) or self-perceived walking limitation (MSWS-12: |r| < 0.19).
PwMS with moderate disability took longer to complete the TUG (18.4 ± 4.1 s vs. 15.9 ± 2.3 s, p = 0.02). Turning duration (2.73 ± 0.49 s vs. 3.20 ± 0.79 s, p = 0.01), peak turning velocity (144.3 ± 30.0 deg/s vs. 129.8 ± 27.4 deg/s, p = 0.05) and turn-to-sit duration (3.53 ± 0.38 s vs. 4.18 ± 0.91 s, p = 0.02) differed between mild and moderate disability groups.
Conclusions: PwMS with more impaired turning duration and velocity described more difficulties with balance and walking. Transitioning from seated to standing was not associated with balance and walking problems. Patients with EDSS 2.5 – 4.0 demonstrated greater turning impairments compared to the 0 – 2.0 group. Further studies should determine whether a rehabilitation approach targeting turning in MS could result in improved balance confidence, decreased walking limitations, less falls, and increased independence.