BACKGROUND: No previous studies have implemented a standard blood flow restriction (BFR) training session in people with severe haemophilia (PwH), where this type of training has been contraindicated.
OBJECTIVE: The purpose of this study was to evaluate the tolerability, adverse events, and neuromuscular and perceptual responses to an acute session of low load (LL) knee extensions with BFR in PwH under prophylaxis.
METHODS: Eight PwH performed one LL-BFR session with 40% arterial occlusion pressure (AOP). Perceptual responses and adverse effects were assessed, together with high-density surface electromyography of vastus medialis (VM) and lateralis (VL).
RESULTS: Significant normalized root mean square differences were found within each set, but not between sets. Spatial distribution (centroid displacement (p > .05), modified entropy (VM, set two, cycles three and five, p = .032) and coefficient of variation (VM, set two, cycles four and five lower than cycle three (p = .049; p = .036)) showed changes within each set. Median frequency showed a slight increase during cycle four of set four (p = .030). Rate of perceived exertion slightly increased with each set while tolerability slightly decreased in the last set and fear of training with BFR generally decreased after the session.
CONCLUSIONS: In PwH, a LL-BFR session at 40% AOP is safe and feasible. Our results suggest that potential muscle impairments may blunt neuromuscular adaptations induced by BFR.

In order to better design handling-assisted exoskeletons, it is necessary to analyze the biomechanics of human hand movements. In this study, Anybody Modeling System (AMS) simulation was used to analyze the movement state of muscles during human handling. Combined with surface electromyography (sEMG) experiments, specific analysis and verification were carried out to obtain the position of muscles that the human body needs to assist during handling. In this study, the simulation and experiment were carried out for the manual handling process. A treatment group and an experimental group were set up. This study found that the vastus medialis muscle, vastus lateralis muscle, latissimus dorsi muscle, trapezius muscle, deltoid muscle and triceps brachii muscle require more energy in the process of handling, and it is reasonable and effective to combine sEMG signals with the simulation of the musculoskeletal model to analyze the muscle condition of human movement.

UNASSIGNED: This meta-analysis aims to systematically evaluate the impact of blood flow restriction training (BFRT) on muscle activation and post-activation potentiation (PAP) in the upper limbs, to provide guidance for upper limb protocols aiming to enhance explosive strength and activation.
UNASSIGNED: PubMed, CNKI, Web of Science, and EBSCO databases were queried to identify randomized controlled trials (RCTs) investigating the effects of upper limb BFRT on muscle activation and PAP. Inclusion and exclusion criteria were applied using the Cochrane bias risk tool. Literature quality assessment and statistical analysis were conducted using Revman 5.4 and Stata 17.0 software. Sensitivity analysis and funnel plots were utilized to assess result stability and publication bias.
UNASSIGNED: A total of 31 articles involving 484 participants were included in the analysis. Meta-analysis results showed that upper limb BFRT significantly increased muscle iEMG values [SMD = 0.89, 95%CI (0.21, 1.58), p = 0.01]. BFRT had a significant effect on upper limb explosive force [SMD = 0.73, 95%CI (0.41, 1.04), p < 0.00001]. Subgroup analysis based on literature heterogeneity (I 2 = 92%, 80%) showed that exhaustive BFRT significantly decreased upper limb iEMG [SMD = -0.67, 95%CI (-1.25, -0.09), p = 0.01], with exercise modes including maximum output power of bench press [SMD = 1.87, 95%CI (0.22, 3.53), p < 0.0001], exercise intensity of 40%-70% 1RM [SMD = 1.31, 95%CI (0.61, 2.01), p < 0.0001], and pressure intensity of ≥60% AOP [SMD = 0.83, 95%CI (0.43, 1.23), p < 0.0001] reaching maximum effects and statistical significance.
UNASSIGNED: Upper limb BFRT can induce muscle activation and PAP. BFRT with 40%-70% 1RM and ≥60% AOP in the upper limbs is more likely to promote PAP.
UNASSIGNED: http://inplasy.com, identifier INPLASY202430008.

BACKGROUND: Frozen shoulder (FS) is characterized by restricted active and passive shoulder mobility and pain.
OBJECTIVE: Compare the effect of muscle-biased manual therapy (MM) and regular physical therapy (RPT) in patients with FS.
METHODS: Pretest-post-test control group study design.
METHODS: We recruited 34 patients with FS and compared the effect of 12-session MM and RPT. The outcome measures were scapular kinematics and muscle activation, scapular alignment, shoulder range of motion, and pain intensity. Two-way analysis of variance was used to examine the intervention effect with α = 0.05.
RESULTS: Both programs resulted in similar improvements in pain and shoulder function. Compared to the RPT, MM resulted in increased posterior tilt (MM: 7.04°-16.09°, RPT: -2.50° to -4.37°; p = 0.002; ES = 0.261) and lower trapezius activation (MM: 260.61%-470.90%, RPT: 322.64%-313.33%; p = 0.033; ES = 0.134) during scaption, and increased posterior tilt (MM: 0.70°-15.16°, RPT: -9.66° to -6.44°; p = 0.007; ES = 0.205) during the hand-to-neck task. The MM group also showed increased GH backward elevation (MM: 37.18°-42.79°, RPT: 43.64°-40.83°; p = 0.004, ES = 0.237) and scapular downward rotation (MM: -2.48° to 6.80°, RPT: 1.93°-1.44°; p < 0.001; ES = 0.404) during the thumb-to-waist task, enhanced shoulder abduction (MM: 84.6°-102.3°, RPT: 85.1°-92.9°; p = 0.02; ES = 0.153), and improved scapular alignment (MM: 10.4-9.65 cm, RPT: 9.41-9.56 cm; p = 0.02; ES = 0.114).
CONCLUSIONS: MM was superior to the RPT regarding scapular neuromuscular performance. Clinicians should consider adding muscle-biased treatment when treating FS.

To date, most studies examined the effects of cold water immersion (CWI) on neuromuscular control following exercise solely on measuring proprioception, no study explores changes in the brain and muscles. The aim of this study was to investigate the effects of CWI following exercise on knee neuromuscular control capacity, and physiological and perceptual responses. In a crossover control design, fifteen participants performed an exhaustion exercise. Subsequently, they underwent a 10 min recovery intervention, either in the form of passively seated rest (CON) or CWI at 15 °C. The knee proprioception, oxygenated cerebral hemoglobin concentrations (Δ[HbO]), and muscle activation during the proprioception test, physiological and perceptual responses were measured. CWI did not have a significant effect on proprioception at the post-intervention but attenuated the reductions in Δ[HbO] in the primary sensory cortex and posterior parietal cortex (p < 0.05). The root mean square of vastus medialis was higher in the CWI compared to the CON. CWI effectively reduced core temperature and mean skin temperature and improved the rating of perceived exertion and thermal sensation. These results indicated that 10 min of CWI at 15 °C post-exercise had no negative effect on the neuromuscular control of the knee joint but could improve subjective perception and decrease body temperature.

BACKGROUND: Standardised guidelines for stance are used to improve interobserver reliability in anthropometric measurements in clinical practice. A key feature of the stance in Pilates is the \'drawing in and up\' of the abdomen. The aim of this study was to study the impact of the Pilates stance on height, waist circumference and interscapular distance, compared to that recommended in clinical practice.
METHODS: 48 healthy females (median age 60 years) were assessed before and after 10-week Pilates-based matwork training. One Pilates expert and one novice took independent measurements of weight, height, waist circumference and interscapular distance (ISD).
RESULTS: Pilates stance, compared to Normal, increased height by up to 2.7 cm and decreased waist up to 5.2 cm (each P < 0.001, repeated measures ANOVA). ISD decreased up to 14 mm (P < 0.001) and this decrease was greater after training (P < 0.001). After controlling for age and length of time learning Pilates, greater baseline ISD predicted a greater change in ISD after the intervention. Effect of Pilates stance was greater when the expert took the measurements (each P ≤ 0.001).
CONCLUSIONS: Activation of trunk muscles in the Pilates stance increases height and decreases waist circumference, compared to the stance recommended in UK healthcare settings. A decrease in ISD was observed, which was greater after a Pilates-based matwork programme. There are significant inter-observer differences, therefore current clinical guidelines for stance are recommended for repeated anthropometry. The value of the Pilates stance in improving posture and the role of ISD as a marker, should be further studied in various contexts, including clinical settings.

OBJECTIVE: Our study aimed to compare the immediate and prolonged effects of submaximal eccentric (ECC) and concentric (CON) fatiguing protocols on the etiology of hamstrings\' motor performance fatigue.
METHODS: On separate days, 16 males performed sets of 5 unilateral ECC or CON hamstrings\' contractions at 80% of their 1 Repetition Maximum (1 RM) until a 20% decrement in maximal voluntary isometric contraction (MVC) torque was reached. Electrical stimulations were delivered during and after MVCs at several time points: before, throughout, immediately after (POST) and 24 h (POST 24) after the exercise. Potentiated twitch torques (T100 and T10, respectively) were recorded in response to high and low frequency paired electrical stimulations, and hamstrings\' voluntary activation (VA) level was determined using the interpolated twitch technique. For statistical analysis, all indices of hamstrings\' motor performance fatigue were expressed as a percentage of their respective baseline value.
RESULTS: At POST, T100 (ECC: -13.3%; CON: -9.7%; p < 0.001), T10 (ECC: -5.1%; CON: -11.8%; p < 0.05) and hamstrings\' VA level (ECC: -3.0%; CON: -2.4%; p < 0.001) were significantly reduced from baseline, without statistical differences between fatigue conditions. At POST24, all indices of hamstrings\' motor performance fatigue returned to their baseline values.
CONCLUSIONS: These results suggest that the contribution of muscular and neural mechanisms in hamstrings\' motor performance fatigue may not depend on contraction type. This may have implications for practitioners, as ECC and CON strengthening could be similarly effective to improve hamstrings\' fatigue resistance.

BACKGROUND: Class II subdivision is a malocclusion characterized by dental and functional asymmetry that is difficult to manage. Impaired muscle function can result in asymmetrical growth, leading to occlusal instability.
OBJECTIVE: The study aimed to assess occlusal force in patients with Class II subdivision malocclusion using Innobyte. Additionally, the discrepancies of force generated at the position of maximum intercuspidation between the left and right sides of the arches were evaluated.
METHODS: The occlusal force of 66 patients with Class II subdivision malocclusion (group S) was measured and compared with that of 66 patients with Class I (group I) and 66 patients with Class II malocclusion (group II). The S group patients had a Class I molar on the right side and a Class II molar on the left side. ANOVA test, followed by the Games-Howell post hoc test, was performed to compare the mean of the total force among the groups. To assess the difference in force between the right and left arches, one-way ANOVA test followed by Tukey\'s post hoc comparison was performed. Finally, a boxplot was created to show the trend of occlusal force recorded in the three groups of patients.
RESULTS: The occlusal force differed significantly among the groups (p < .001). Post hoc Games-Howell analysis showed significant differences as follows: the total force in group S was 165.24 N greater than in group II and in group I was 218.06 N greater than in group II. The difference (right-left) in total force between the groups was statistically significant (p < .001). Tukey\'s post hoc test showed following significant correlation: in group S was 53.51 N greater than in group II and 63.12 N greater than in group I.
CONCLUSIONS: Among the analysed groups, patients with Class II malocclusion exhibited the lowest value of occlusal force. In patients with Class II subdivision malocclusion, force asymmetry, characterised by a higher value on the Class I side and a lower value on the Class II side was observed.

BACKGROUND: Motor unit (MU) activation during maximal contractions is lower in children compared with adults. Among adults, discrete MU activation differs, depending on the rate of contraction. We investigated the effect of contraction rate on discrete MU activation in boys and men.
METHODS: Following a habituation session, 14 boys and 20 men completed two experimental sessions for knee extension and wrist flexion, in random order. Maximal voluntary isometric torque (MVIC) was determined before completing trapezoidal isometric contractions (70%MVIC) at low (10%MVIC/s) and high (35%MVIC/s) contraction rates. Surface electromyography was captured from the vastus lateralis (VL) and flexor carpi radialis (FCR) and decomposed into individual MU action potential (MUAP) trains.
RESULTS: In both groups and muscles, the initial MU firing rate (MUFR) was greater (p < 0.05) at high compared with low contraction rates. The increase in initial MUFR at the fast contraction in the VL was greater in men than boys (p < 0.05). Mean MUFR was significantly lower during fast contractions only in the FCR (p < 0.05). In both groups and muscles, the rate of decay of MUFR with increasing MUAP amplitude was less steep (p < 0.05) during fast compared with slow contractions.
CONCLUSIONS: In both groups and muscles, initial MUFRs, as well as MUFRs of large MUs were higher during fast compared with slow contractions. However, in the VL, the increase in initial MUFR was greater in men compared with boys. This suggests that in large muscles, men may rely more on increasing MUFR to generate torque at faster rates compared with boys.

BACKGROUND: Goalball is a popular sport among visually impaired individuals, offering many physical and social benefits. Evaluating performance in Goalball, particularly understanding factors influencing ball velocity during throwing techniques, is essential for optimizing training programs and enhancing player performance. However, there is limited research on muscle activation patterns during Goalball throwing movements, needing further investigation to address this gap. Therefore, this study aims to examine muscle activity in sub-elite visually impaired Goalball players during different throwing techniques and visual conditions, focusing on its relationship with ball velocity.
METHODS: 15 sub-elite Goalball players (2 female, 13 males; mean age of 20.46 ± 2.23 years) participated in the study. Muscle activity was evaluated with the Myo armband, while ball velocity was measured using two cameras and analyzed with MATLAB software. Different visual conditions were simulated using an eye band, and the effects of these conditions on muscle activation and ball velocity were examined.
RESULTS: The flexor muscles were found to be more active during the spin throw techniques with the eyes open (p = 0.011). The extensor muscles were found to be more active in the eyes-closed spin throw techniques compared to the eyes-open position (p = 0.031). Ball velocity was found related to the flexor muscles. Interestingly, no significant differences in ball velocity were observed between different throwing techniques or visual conditions (p > 0.05).
CONCLUSIONS: Ball velocity, one of the performance indicators of the athlete, is primarily related to upper extremity flexor muscle strength rather than visual acuity. It has less visual acuity, but an athlete with more upper-extremity flexor muscle strength will have an advantage in Goalball game. The spin throw technique, which is reported to provide a biomechanical advantage for professional players in the literature, did not provide an advantage in terms of ball velocity for the sub elite players evaluated in our study. This knowledge can inform the development of targeted training programs aimed at improving technique and enhancing ball velocity in Goalball players.