Introduction: Excessive load on the backpacks can lead to musculoskeletal injuries and gait alterations. The objective of this study was to analyze the electromyographic (EMG) activity in association to the kinematic during the stance and balance phases of gait performed with and without the use of the backpack. Methods: Twelve volunteers have executed a gait cycle in 3 tasks: without the school backpack (SM), with a backpack with load equivalent to 10% (M10) and 20% (M20) of the body weight (BW). It was evaluated the ankle, knee and hip angular excursion (AE), linear displacement (LD) of the toe and ankle, knee, hip, shoulder, head and EMG activity of the tibialis anterior (TA), vastus medialis (VM), rectus abdominis (RA), gastrocnemius lateral (GL), biceps femoris (BF) and spinal erector (EE) muscles. Results: In the LD in the stance phase there was an AP increase for the toe and ankle, hip and head (p<0.043). In the balance phase for VT (vertical) direction, the shoulder presented a smaller displacement as well as the toe, ankle, knee, hip, shoulder and head in the ML direction. In the AP direction, the toe displacement was smaller as well as the ankle (p < 0.038). The AE in both phases was smaller for the hip (p <0.006). In the balance phase the IEMG was higher for the RA (p = 0.034). Conclusion: These results suggest that the transport of school backpacks with loads of more than 10%BW causes changes in the kinematic and in the muscular recruitment pattern.

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Background The effect of hyperalgesia on functionality remains uncertain for individuals with knee osteoarthritis (KOA). This study aimed examine the clinical measures and hyperalgesia’s effect on muscle activity, knee range of motion (ROM) and postural control during the single-leg mini squat (SLMS) in individuals with KOA, determining the correlation between variables. Methods In this cross-sectional study, 60 individuals, 30 healthy (HG, 57.4 ± 6.86 years), and 30 with mild to moderate KOA (KOAG, 59.4 ± 5.46 years) were evaluated by the visual analog scale (VAS), Western Ontario and McMaster Universities Index (WOMAC), and the pressure pain threshold (PPT) in subcutaneous, myotomal, and sclerotomal structures. Muscle activity, knee ROM and postural control were assessed during a SLMS. The analyses were performed in the two phases of the SLMS. Phase 1 - during descending movement (eccentric contraction), Phase 2 - during ascending movement (concentric contraction). Analysis of covariance was applied for each variable separately, using weight as a co-variable. We used Spearman’s test for determining the correlation. Results There was no difference between groups for age, height, and postural control (p > 0.059), but KOAG presented the highest values for VAS and WOMAC (p = 0.000). In addition, EMG activity was higher in KOAG for gastrocnemius medialis and tibialis anterior muscles during phase 1 (p < 0.027), and for gastrocnemius medialis and gluteus medius muscles during phase 2 (p < 0.007), and reduced values for PPT and knee ROM (p = 0.000). Also, the correlations between PPT with muscle activity and postural control were moderate (rho< 0.482), while strong relationships were observed between some PPT points with VAS and WOMAC (rho> 0.507). Conclusion Hyperalgesia affects the functionality during a single-limb mini squat. There is an important correlation between hyperalgesia and muscle activity, postural control, and clinical measures in individuals with KOA.

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Objectives: Fatigue is the most common and disabling symptom for people with multiple sclerosis (MS) and female gender is correlated with higher reported fatigue severity. This study analyzes fatigue severity in adult women with MS and identifies significant differences between centers on mean fatigue severity scores. Methods: We conducted a prospective 1-year baseline study across four MS-CQI centers (A,B,C,D). Participants were adult females (18+) with MS. Fatigue severity was measured using the Promis Fatigue MS Patient-Reported Outcome Measure (PROM). Descriptive statistics were evaluated for each center, as well as significance testing across and between centers. Continuous variables were analyzed using ANOVA, and categorical variables were analyzed using Chi-Square tests. Results: 322 female MS patients were in the sample. 211 (65.5%) were white, 118 (36.6%) had full-time employment, 165 (51.2%) were married, 85 (26.4%) had an annual income of $50,000-$99,999, 222 (68.9%) were English-speaking, 27 (8.4%) lived alone, and 265 (82.3%) had employer health insurance. Socioeconomic variables demonstrating statistical significance (Chi-Square p,0.0001) included race, employment, marital status, language, housing, insurance and education. Significant center-level variation were also found compared to overall MS-CQI mean fatigue severity (ANOVA F=7.31, p,0.0001). Tukey's Honest Significant Difference tests (HSD) revealed statistically significant differences (p,0.0001) between centers C-B, D-B, A-B, B-C, B-D, and B-A (Critical Value=3.65). Conclusions: Results suggest significant center-level differences in mean fatigue scores across and between centers. Future research is needed to investigate the factors influencing these differences and test the effects of targeted center-level improvement interventions on reducing population fatigue severity levels.