Interplay between balance, gait kinematic and physical activity level in facioscapulohumeral muscular dystrophy

Balance impairments can affect walking ability and, consequently, limit physical activity level (PAL). This investigation in facioscapulohumeral muscular dystrophy (FSHD) may help unravel factors limiting PAL and identify new rehabilitation strategies to improve mobility in these patients. Eighteen FSHD patients (10 males; mean age: 36.33 years) and twenty-three age- and sex-matched healthy controls (HC) were recruited. Balance was assessed using the Mini-BEST and Four Step Square test (FSST), while PAL was measured with the International Physical Activity Questionnaire. Gait performance during usual walking (UW), fast walking (FW), and dual-task walking (DT) was evaluated using an inertial sensor (BTS G-Walk). Gait speed (GS), stance time (ST), gait cycle (GC), stride length (SL), pitch and roll angles were considered. Correlations between gait parameters and Mini-BEST were performed in patients, while between PAL, GS, and SL were assessed in both groups. Compared to HC, patients showed lower PAL, Mini-BEST scores and longer FSST times. As group effect, patients exhibited major ST, GC, and roll angle. In the interaction between group and walking condition, during FW patients showed reduced GS and prolonged GC, while no differences were observed in UW and DT. Altered gait parameters, except roll angle, were associated with Mini-BEST, while PAL correlated with gait parameters only in HC. Balance resulted associated with impaired gait parameters in FSHD. The association between balance and gait deficits emerging during FW indicate balance impairment as an element discouraging patients from engaging in physically demanding tasks, plausibly decreasing PAL.