Effects of maturity status on the rate of torque development in young male soccer players.

Background: The rate of torque development (RTD) has been associated with sports performance and can be improved during the biological maturation process of young soccer players. The aim of this study was to compare the effects of maturity status on the knee extensors' RTD of soccer players after appropriate normalization.

Methods: Twenty-seven young male soccer players aged 13-18 years old were allocated into two groups: pubescent (PUB, n = 11) and postpubescent (POSP, n = 16).

Motor Point as an Alternative to Femoral Nerve Stimulation for the Assessment of Quadriceps Muscle Inhibition in Healthy Women.

Context: The evaluation of quadriceps muscle inhibition with the interpolated twitch technique is usually performed by stimulating the femoral nerve (FN). However, there are some problems related to the use of this stimulation site, which may be partially overcome by delivering the stimulation over the motor point (MP). This study sought to compare MP to FN stimulation at different joint angles for the evaluation of quadriceps muscle inhibition, resting peak torque, and discomfort in healthy women.

Do athletes with hamstring strain injury have shorter muscle fascicles in the injured limb?

Introduction: Previous studies have suggested that a reduced length of the biceps femoris long head (BF) fascicles may increase the risk of hamstring strain injury (HSI). However, it remains unclear whether the BF fascicles of the injured limb are shorter than those of the contralateral limb in athletes with an acute HSI.

Objective: To investigate the between-limb asymmetry of BF fascicle length in amateur athletes with an acute HSI.

Can a clinical assessment predict the functional status progression in patients with femoroacetabular impingement syndrome?

Background: Femoroacetabular impingement syndrome (FAIS) is a hip joint motion-related clinical disorder with a triad of symptoms, clinical signs, and imaging findings. However, scientific evidence is still unclear regarding the best treatment for FAIS.

Objectives: To assess the value of a physical therapy evaluation in predicting the progression of functional status over the subsequent years in patients with FAIS who are candidates for hip arthroscopy surgery.

Anthropometric, neuromuscular, physiologic and training variables as determinants to laboratory cycling performance.

Background: The goal of this study was to verify whether anthropometric, physiological and neuromuscular factors, as well as training characteristics, could predict cycling performance during maximal incremental and time-to-exhaustion tests.

Methods: Twenty cyclists were evaluated: Anthropometric variables, knee extensor muscle activation and architecture, training history, and training volume were assessed. Second ventilatory threshold (VT2), maximal oxygen uptake (VO2MAX), and maximal power output (POMAX) were assessed during the incremental test.

Effects of Photobiomodulation Therapy on Performance in Successive Time-to-Exhaustion Cycling Tests: A Randomized Double-Blinded Placebo-Controlled Trial.

The goal of this study was to investigate the effects of photobiomodulation therapy (PBMT) on performance, oxygen uptake (VO) kinetics, and lower limb muscle oxygenation during three successive time-to-exhaustions (TTEs) in cyclists. This was a double-blind, randomized, crossover, placebo-controlled trial study. Sixteen cyclists (~23 years) with a cycling training volume of ~460 km/week volunteered for this study.

Single-Leg Squat Test in the Clinical Setting Does Not Discriminate Patients With Femoroacetabular Impingement Syndrome From Asymptomatic Individuals.

Context: Laboratorial 3-dimensional kinematic analyses have shown changes in the single-leg squat's (SLS) pattern of patients with femoroacetabular impingement syndrome (FAIS). However, it is unknown whether clinicians are able to detect these changes using 2-dimensional kinematics.

Objective: To compare the frontal plane 2-dimensional kinematics of patients with FAIS and asymptomatic individuals in the SLS test performed in a clinical setting.

Quadriceps Muscle Morphology Is an Important Determinant of Maximal Isometric and Crank Torques of Cyclists.

The aim of this study was to determine if quadriceps morphology [muscle volume (MV); cross-sectional area (CSA)], vastus lateralis (VL) muscle architecture, and muscle quality [echo intensity (ECHO)] can explain differences in knee extensor maximal voluntary isometric contraction (MVIC), crank torque (CT) and time-to-exhaustion (TTE) in trained cyclists. Twenty male competitive cyclists performed a maximal incremental ramp to determine their maximal power output (PO). Muscle morphology (MV; CSA), muscle architecture of VL and muscle quality (ECHO) of both quadriceps muscles were assessed.

Kilohertz Frequency Alternating Current Induces Less Evoked Torque and Less Neuromuscular Efficiency Than Pulsed Current in Healthy People: A Randomized Crossover Trial.

Context: Pulsed current and kilohertz frequency alternating current are 2 types of neuromuscular electrical stimulation (NMES) currents often used by clinicians during rehabilitation. However, the low methodological quality and the different NMES parameters and protocols used in several studies might explain their inconclusive results in terms of their effects in the evoked torque and the discomfort level. In addition, the neuromuscular efficiency (ie, the NMES current type that evokes the highest torque with the lowest current intensity) has not been established yet.

Hip Joint Biomechanical Parameters and Their Relationship With the Esthetic Functional Performance of the Développé à la Seconde Movement in Classical Ballet Dancers.

Développé à la seconde is a classic ballet movement that requires the maintenance of a high hip joint range of motion (ROM) and muscle strength. However, the contribution of these hip joint biomechanical parameters to this movement's esthetic performance is unclear. Therefore, this study evaluated hip joint biomechanical characteristics of 21 experienced ballet dancers (15-29 y old) and verified the relationship between these variables with the développé à la seconde static and dynamic performance.

Eccentric, but not concentric muscle contraction induce inflammation and impairs fibrinolysis in healthy young men.

Different types of muscle contraction can cause different damage to the musculature and differences in inflammatory responses. Acute increases in circulatory inflammation markers can influence the crosstalk between coagulation and fibrinolysis processes, increasing the risk of thrombus formation and detrimental cardiovascular events. The aim of this study was to analyze the effects of concentric and eccentric exercise on hemostasis markers, C-reactive protein (CRP), and the relationship between these variables.

Distal overactivation of gastrocnemius medialis in persistent plantarflexion weakness following Achilles tendon repair.

Structural alterations of the triceps surae and Achilles tendon (AT) can promote plantarflexion weakness one-year following an AT repair, influencing the activation strategies of the Gastrocnemius Medialis (GM) muscle. However, this is yet to be demonstrated. We aimed to determine whether patients with plantar flexion weakness one-year after AT repair show altered GM spatial activation.

Foam Rolling Acute Effects on Myofascial Tissue Stiffness and Muscle Strength: A Systematic Review and Meta-Analysis.

Glänzel, MH, Rodrigues, DR, Petter, GN, Pozzobon, D, Vaz, MA, and Geremia, JM. Foam rolling acute effects on myofascial tissue stiffness and muscle strength: a systematic review and meta-analysis. J Strength Cond Res 37(4): 951-968, 2023-Foam rolling (FR) is widely used in rehabilitation and physical training.

Can we replace exercises targeted on core/hip muscles by exercises targeted on leg/foot muscles in women with patellofemoral pain? A randomized controlled trial.

Objective: To verify the effects of replacing exercises targeted on core/hip muscles by exercises targeted on leg/foot muscles in a rehabilitation program for patellofemoral pain (PFP).

Design: Randomized Controlled Trial.

Participants: Fifty women with PFP.

Do femoral version abnormalities play a role in hip function of patients with hip pain?

Background: A high prevalence of femoral version abnormalities has been observed in hip pain patients, with impact on hip range of motion and muscle strength that should be elucidated.

Methods: Cross-sectional study. Thirty-one patients with hip pain (16 men and 15 female) were subjected to Biplanar X-Rays to quantify femoral version using three-dimensional measurements.

Are the Harris Hip Score and the Hip Outcome Score valid patient-reported outcome measures for femoroacetabular impingement syndrome?

Background: The International Hip Outcome Tool (iHOT-33) is a reference instrument among the Patient-Reported Outcome Measures (PROMs) to assess people with hip disorders, including femoroacetabular impingement (FAI) syndrome. Older questionnaires such as the Harris Hip Score, or its modified version (mHHS), and the Hip Outcome Score (HOS), through the full version or its subscales (Activities of Daily Living-ADL; and Sports) are still used in the clinical setting and their construct validity is so far underexplored.

Objective: To assess the construct validity of mHHS and HOS-ADL compared with iHOT-33 by hypothesis testing in a large sample of patients with FAI syndrome.

Effects of Kilohertz Frequency, Burst Duty Cycle, and Burst Duration on Evoked Torque, Perceived Discomfort and Muscle Fatigue: A Systematic Review.

Kilohertz-frequency alternating current is used to minimize muscle atrophy and muscle weakness and improve muscle performance. However, no systematic reviews have evaluated the best Kilohertz-frequency alternating current parameters for this purpose. We investigated the effects of the carrier frequency, burst duty cycles, and burst durations on evoked torque, perceived discomfort, and muscle fatigue.

Effects of workload level on the timing of concentric-eccentric contractions during cycling.

Background: The mechanical energy required to drive the cranks during cycling depends on concentric and eccentric muscle actions. However, no study to date provided clear evidence on how workload levels affect concentric and eccentric muscle actions during cycling. Therefore, the aim of this study was to investigate the workload effects on the timing of lower limb concentric and eccentric muscle actions, and on joint power production.

Triceps Surae Muscle-Tendon Properties as Determinants of the Metabolic Cost in Trained Long-Distance Runners.

This study aimed to determine whether triceps surae's muscle architecture and Achilles tendon parameters are related to running metabolic cost (C) in trained long-distance runners. Seventeen trained male recreational long-distance runners (mean age = 34 years) participated in this study. C was measured during submaximal steady-state running (5 min) at 12 and 16 km h on a treadmill.

Development and reliability of a new system for bedside evaluation of non-volitional knee extension force.

Purpose: Neuromuscular electrical stimulation (NMES) is a widely-used technique for diagnostic and therapeutic purposes. Here we developed and tested the reliability of a new NMES-dynamometer system for bedside evaluation of knee extensor muscle function.

Materials And Methods: Thirty-two healthy participants (16 men, 16 women; 27±5 years) completed two testing sessions, 7 days apart.

Triceps surae muscle-tendon unit mechanical property changes during 10 minutes of streching.

Objective: To verify the effect of 10-min static stretching on the triceps surae mechanical properties.

Design: Quasi-experimental one-group pre test-post test study compared the time points of before, after, and minute by minute of one session of triceps surae passive static stretching.

Methods: 15 participants performed a 10-min plantar flexor passive static stretching on the isokinetic dynamometer.