RESUMEN
BACKGROUND: This study aimed at quantifying ankle plantarflexors' resistance to passive motion (RPM) by isokinetic dynamometry and muscle activity through surface electromyography (sEMG) in persons with multiple sclerosis (PwMS) with limb stiffness and spasticity. METHODS: Slow and fast ankle dorsiflexions (from 5°/s to 210°/s) were imparted passively by an isokinetic dynamometer, and sEMG activity of plantarflexors was recorded at the same time as the square root of the moving average. Based on RPM evaluated at 5°/s, ankles were classified as more- and less-resistant as measured by average peak torque (APT). RESULTS: Measurements were obtained bilaterally from 24 PwMS (median EDSS: 5.5) with median Modified Ashworth Scale (MAS) score of 1.75. Compared to the lowest velocity inducing EMG-evident responses (120°/s), RPM increased significantly at 180°/s (+137.8 %; p < 0.0005) and 210°/s (+85.3 %; p < 0.0005) in the less-resistant side, and only at 210°/s (+113.8 %; p < 0.0005) in the more-resistant side. sEMG activity increased significantly and similarly between limbs at increasing velocities. Significant velocity-dependent increases were detected in both limbs, with no difference by side, at 180°/s (+34.5 %; p = 0.005) and 210°/s (+48.4 %; p = 0.004). Regression analyses confirmed side (ß=0.542; p < 0.0001) and speed (ß=0.238; p < 0.0001) as significant predictors of APT change, but only speed for sEMG (speed: ß=0.215; p = 0.019; side: ß=0.012; p = 0.893). Bivariate correlations revealed that RPM was associated negatively with MAS and positively with sEMG. CONCLUSION: Spasticity presented bilaterally in PwMS, with different mixed pictures of passive and reflex stiffness, both requiring attention. Combining isokinetics and sEMG allows detecting even subtle, subclinical alterations that can prompt and drive early tailored management.
RESUMEN
PURPOSE: To evaluate the effects of wild trekking by examining, in postmenopausal women, the physiological adaptations to an intensive 5-day wild trek and comparing their responses to those displayed by a group of men of comparable age, training status and mountaineering skills. METHODS: Six healthy, active postmenopausal women in their sixth decade of life participated in the study. Six men of comparable age and training status were also enrolled for gender-based comparisons. The participants traversed the Selvaggio Blu wild trek (Sardinia, Italy) completing a total of 56 km, for an overall height differential of 14,301 m. During all 5-day trek, subjects were supervised by two alpine guides. Changes in body composition, cardiorespiratory fitness, and metabolic patterns of energy expenditure were evaluated before and after the intervention. RESULTS: Total energy expenditure during the trek was significantly higher (p = 0.03) in women (12.88 ± 3.37 kcal/h/kg) than men (9.27 ± 0.89 kcal/h/kg). Extracellular (ECW) and intracellular water (ICW) increased significantly following the trek only in women (ECW: - 3.8%; p = 0.01; ICW: + 3.4%; p = 0.01). The same applied to fat-free mass (+ 5.6%; p = 0.006), fat mass (- 20.4%; p = 0.006), skeletal muscle mass (+ 9.5%; p = 0.007), and appendicular muscle mass (+ 7.3%; p = 0.002). Peak VO2/kg (+ 9.4%; p = 0.05) and fat oxidation (at 80 W: + 26.96%; p = 0.04; at 100 W: + 40.95%; p = 0.02; at 120 W: + 83.02%; p = 0.01) were found increased only in women, although no concurrent changes in partial pressure of end-tidal CO2 (PETCO2) was observed. CONCLUSIONS: In postmenopausal women, a 5-day, intensive and physically/technically demanding outdoor trekking activity led to significant and potentially relevant changes in body composition, energy balance and metabolism that are generally attained following quite longer periods of training.