Tomohiro Ishida

Objectives: Physical activity management through smartphone applications is increasing worldwide; however, it is unclear whether smartphone users among elderly Japanese individuals with musculoskeletal disorders are less likely to experience “locomotive syndrome” (LoS). We aimed to test the hypothesis that LoS in smartphone users had lower prevalence than that in non-smartphone users among elderly individuals with musculoskeletal disorders. Methods: Elderly participants, aged ≥60 years, who visited the outpatient clinic were enrolled. All participants were asked whether or not they used smartphones and were allocated into either the smartphone group or the non-smartphone group. After completing the 25-question Geriatric Locomotive Function Scale (GLFS-25), LoS prevalence was determined by 3-stage cutoff values of the GLFS-25 score (≥7, ≥16, and ≥24), and the total and three subdomain scores (body pain, movement-related difficulty, and psychosocial complications) were compared between the two groups. Generalized linear regression was then performed to confirm whether the use of smartphones was associated with lower GLFS-25 scores, even after controlling for confounders. Results: Overall, 266 participants, aged ≥60 years, were recruited. LoS prevalence was significantly higher in the non-smartphone group than in the smartphone group at all stages (all p < 0.001). Mean GLFS-25 total and subdomain scores were significantly lower in the smartphone group than in the non-smartphone group (all p < 0.001), and these statistical relationships were maintained even after controlling for age and sex. Conclusions: Smartphone use was associated with low LoS prevalence and low GLFS-25 scores among elderly individuals with musculoskeletal disorders, although the causal relationship remains unclear.

Background: We aimed to determine a cut-off value for physical activity (PA), measured using an accelerometer, between patients with knee osteoarthritis (OA) who decided to undergo total knee arthroplasty (TKA) and those who continued conservative treatment. Methods: Forty-two participants were assigned to either a TKA group or a non-TKA group (21 per group). They were instructed to wear an accelerometer throughout the day. Average daily steps (steps/day), average daily time of light PA (LPA) (min/day), and average daily time of moderate-to-vigorous PA (MVPA) (min/day) were measured for seven days. Variables between the two groups were compared using univariate analyses, and then a stepwise logistic regression was conducted to determine which variables best correlated with undergoing TKA. The PA cut-offs were analysed using the receiver operating characteristic curve. Results: Pain severity (p = 0.002), KL grade (p = 0.001), and MVPA (p = 0.012) differed significantly between the groups. The most useful cut-off value was 5.84 (min/day) for MVPA (AUC = 0.773), although only pain severity and KL grade were found to be significant contributors to undergoing TKA. Conclusions: Our results revealed there was a significant decrease in PA levels (MVPA cut-off, 5–6 min/day) in the TKA group compared with the non-TKA group.