Different authors have modelled myofascial tissue connectivity over a distance using cadaveric models, but in vivo models are scarce. The aim of this study was to evaluate the relationship between pelvic motion and deep fascia displacement in the medial gastrocnemius (MG). Deep fascia displacement of the MG was evaluated through automatic tracking with an ultrasound. Angular variation of the pelvis was determined by 2D kinematic analysis. The average maximum fascia displacement and pelvic motion were 1.501 ± 0.78 mm and 6.55 ± 2.47 °, respectively. The result of a simple linear regression between fascia displacement and pelvic motion for three task executions by 17 individuals was r = 0.791 (P < 0.001). Moreover, hamstring flexibility was related to a lower anterior tilt of the pelvis (r = 0.544, P < 0.024) and a lower deep fascia displacement of the MG (r = 0.449, P < 0.042). These results support the concept of myofascial tissue connectivity over a distance in an in vivo model, reinforce the functional concept of force transmission through synergistic muscle groups, and grant new perspectives for the role of fasciae in restricting movement in remote zones.

Objective Strength training is recommended for people with hemophilia; however, published data are anecdotal and have methodological limitations. The purpose of this study was to evaluate the safety and effectiveness of progressive moderate-to-vigorous intensity elastic resistance training on physical function and pain in this patient population. Methods A randomized controlled trial was conducted in a university laboratory setting where 20 patients (17 with severe, 1 with moderate, and 2 with mild hemophilia) aged 21 to 53 years received evaluations at baseline and 8-week follow-up. Participants were allocated to intervention (progressive strength training) or control (usual daily activities) groups. The intervention group trained 2 days per week during 8 weeks with elastic resistance. Intensity during the first 2 weeks was a 20-repetition maximum and increased progressively toward 15, 12, and finally 10 repetition maximum. The primary outcome was muscle strength. Secondary outcomes were the Timed “Up and Go” Test score, sit-to-stand, range of motion, Haemophilia Joint Health Score, kinesiophobia score, global impression of pain change, general self-rated health status, and desire to exercise. Results The intervention group showed greater strength improvements than the control group in almost all of the joints, with moderate to high effect sizes. The intervention group also showed better Timed “Up and Go” and sit-to-stand scores than the control group (moderate effect size), greater range of motion at the knee flexion with the right leg (trivial effect size), and better Haemophilia Joint Health Score at the left knee (small effect size). The intervention group showed greater overall pain reduction, self-rated overall status, and desire to exercise than the control group. Conclusions Progressive strength training with elastic resistance performed twice a week during 8 weeks is safe and effective in people with hemophilia to improve muscle strength and functional capacity, reduce general pain, and improve self-rated health status and desire to exercise. Impact This study provides evidence for the use of a specific strength training regimen for people with hemophilia. Lay Summary People with hemophilia of differing levels of severity, with adequate coverage with clotting factor, can safely engage in progressive strength training and can improve their functioning.

This study examined whether a knee flexor isometric contraction at 20% of maximal voluntary isometric contraction until exhaustion would alter the biceps femoris long head (BFlh) and semitendinosus (ST) active stiffness, assessed using ultrasound-based shear wave elastography. Twelve healthy individuals participated in 2 sessions separated by 7 days. Time to exhaustion was similar in both sessions (day 1: 443.8 ± 192.5 s; day 2: 474.6 ± 131.7 s; p = 0.323). At the start of the fatigue task, the ST showed greater active stiffness than the BFlh (p < 0.001), with no differences between days (p = 0.08). The ST active stiffness then decreased from 40% of the task time to exhaustion (− 2.2 to − 13.3%, p = 0.027) until the end of the task (− 16.1 to − 22.9%, p = 0.012), while no significant changes were noted in the BFlh (p = 0.771). Immediately after the fatigue task, a decrease in active stiffness was observed in the ST (− 11.8 to − 17.8%, p < 0.001), but not in the BFlh (p = 0.551). Results were consistent between the 2 testing sessions (p = 0.07–0.959). The present results indicate that fatigue alters the hamstring active stiffness pattern.

Introduction Effects of haemophilic arthropathy on neuromuscular control during gait are currently unknown. Aims (a) To assess how haemophilic arthropathy affects the complexity of neuromuscular control during gait; (b) To investigate the relationship between complexity of neuromuscular control and joint impairment. Methods Thirteen control subjects (CG) walked overground at their preferred and a slow velocity and thirteen people with haemophilic arthropathy (PWHA) walking at their preferred velocity. Surface electromyography (EMG) was collected from eleven leg muscles. Electromyography variance explained by muscle synergies (sets of co‐activated muscles that can be recruited by a single signal) was calculated by the total variance accounted (tVAF). Three measures were used to evaluate complexity of neuromuscular control: (a) the number of synergies required for tVAF > 90%, (b) tVAF as a function of the number of muscle synergies, and (c) the dynamic motor control index (Walk‐DMC). Impairment of ankle and knee joints was determined by the Haemophilia Joint Health Score (HJHS). Results The same number of the muscle synergies was found for each group (P > 0.05). For both walking velocities tested, tVAF1 was higher in PHWA (P < 0.05). The Walk‐DMC of PWHA was lower than that of the CG for both walking velocities (P < 0.05). For PWHA, no significant correlation was found between HJHS (sum knee and ankle) and Walk‐DMC index (r = −0.32, P = 0.28). Conclusions These results indicate differences between PWHA and CG in the neuromuscular control of gait. The Walk‐DMC and tVAF1 may be useful measures to assess changes in neuromuscular control in response to treatment.