Elbow Flexion Research Articles

THE PHYSICAL AND PSYCHOLOGICAL EFFECTS OF DANCE THERAPY ON MIDDLE-AGED AND OLDER ADULT WITH ARTERIAL HYPERTENSION: A SYSTEMATIC REVIEW

ObjectiveTo systematically review the intervention effect of dance therapy on the physical and psychological health level of middle-aged and older adult with arterial hypertension. MethodsThe databases including the Cochrane Library, PubMed, Web of Science, EBSCO, CNKI, VIP, WANFANG DATA, and Bailianyun Library, which were searched for the randomized controlled trials for identifying the effect of dance intervention on the blood pressure. The literature published from the establishment of the database to May 10, 2023, was collected for analysis. The quality of the literature was evaluated by the Cochrane bias risk assessment tool. ResultsThe blood pressure in the dance intervention group were significantly improved than those of patients in the control group. However, among the mediating variables that influence the effects of dance intervention, its intensity and frequency based on the improvement of aerobic capacity were found high and low respectively, while the research on dance intervention aimed at muscle strength, endurance, and flexibility remains lacking. The movement selection and arrangement of dance therapy could integrate the physical activities with local traditional cultural characteristics. ConclusionsIt is worth noting that in the selection and arrangement of movements, dance therapy can skillfully integrate physical activities with local cultural characteristics. This unique combination not only enriches the content of dance therapy but also deepens people's understanding and recognition of traditional culture. Through this comprehensive dance intervention approach, we hope to comprehensively improve participants' physical and mental health, and promote the inheritance and development of culture.

Correlations among flexibility, stiffness, strength and muscle ultrasound parameters in older males afflicted with hamstrings tightness

IntroductionAge-induced inflexibility may lead to significant mobility impairments and declines in well-being. However, the relationship between the structural and mechanical properties of soft tissue and joint extensibility remains unclear. This study aimed to investigate the correlation between flexibility, muscle tendon unit (MTU) stiffness, muscle ultrasound characteristics, muscle strength, and hamstring flexibility prediction in older males with hamstring inflexibility. MethodsA hundred retired old males (mean age: 67.2 ± 4.9 years) participated in this investigation. Muscle ultrasound, flexibility, MTU stiffness, and knee flexors strength were measured in a single visit. ResultsThe results revealed a modest correlation between straight leg raise (SLR) and biceps femoris fascicle length (FL) elongation (r = 0.222), MTU stiffness (r = -0.401), and eccentric strength (r = 0.219) (all p < 0.05). MTU stiffness, eccentric strength, and FL elongation collectively explained 24.8% of the variance in SLR prediction, while deep fascia thickness predicted MTU stiffness with a variance of 6.4%. ConclusionIn summary, increased SLR was associated with lower MTU stiffness, lengthened FL, and higher eccentric strength. SLR was primarily predicted by MTU stiffness, with lesser contributions from FL elongation and knee flexor eccentric strength in older males experiencing hamstring tightness.

Long-term Outcomes of Complete Tears of the Distal Biceps Tendon: An Analysis of Surgical Management at a Median Follow-up of 14.7 Years.

Surgical repair of full thickness biceps tears has demonstrated adequate outcomes in short and mid-term studies. However, data on the long-term outcomes of full thickness distal biceps injuries and their treatment are currently lacking. The purpose of this study was to report on patient demographics, injury characteristics, and long-term outcomes for patients with full-thickness distal biceps tears. It was hypothesized that complete distal biceps tears managed operatively would demonstrate robust clinical success at long-term follow-up. Case series; Level of evidence, 4. Patients with magnetic resonance imaging-confirmed, complete distal biceps tendon rupture sustained between 1996 and 2016 were identified. Patients were cross-referenced with a regional geographic database. A total of 66 patients (3 female, 63 male) with a median age of 50.8 years (IQR, 41.5-60.4) and a median clinical follow-up of 14.7 years (IQR, 9.6-17.9 years) were included. Patients who sustained a full-thickness distal biceps tendon tear were likely to be in their early 50s, male, right-hand dominant, current/former smokers, and laborers with a history of traumatic injury during an intentional movement. Most of these patients had pain and supination weakness but no loss of range of motion. All included tears were treated operatively. At final follow-up, patients maintained a majority of near-normal range of motion (median total arc of flexion/extension 140° and supination/pronation 80°), excellent elbow flexion strength (91% of patients had full strength), and adequate elbow supination strength (76% of patients had full strength). The overall complication rate was 24%, with 16 out of 66 patients experiencing some type of complication between infection, rerupture, heterotopic ossification, reoperation, and nerve complications. Overall return to work was 98%, and 85% of those who returned to work did so without restrictions. Complete tears of the distal biceps were most common in patients 50 years of age, male sex, right-hand dominant, and current/former smokers. The most common profession was laborer, and injuries were primarily traumatic in nature during intentional activity. Patients managed operatively demonstrated high rates of success at long-term follow-up with respect to elbow function and clinical outcomes.

The dose effectiveness of extracorporeal shockwave on plantar flexor spasticity of ankle in stroke patients: a randomized controlled trial

BackgroundExtracorporeal shockwave therapy (ESWT) has been proven beneficial for post-stroke spasticity (PSS) of ankle plantar flexor muscles. This study aims to investigate the dose-response effectiveness of focused-ESWT and the duration of its effect on the treatment of ankle PSS in stroke patients.MethodsIn this double-blinded randomized controlled trial, stroke patients diagnosed with PSS in the ankle plantar flexor muscles were randomly assigned to two groups. The experimental group received double-dose ESWT (4000 pulses per session) targeting spastic calf muscles, while the control group received half the dose (2000 pulses per session). Both groups underwent four sessions over two weeks. The outcomes, including modified Ashworth Scale (MAS), modified Tardieu Scale (MTS), passive range of motion (PROM) of the ankle, Timed Up and Go (TUG) Test, Barthel index and strain elastography were evaluated at baseline, 1st, 4th, 12th, and 24th week after ESWT.ResultsWithin-group analysis revealed significant improvements in MAS, PROM, TUG Test, and Barthel index for the double-dose ESWT group and improvements in Barthel index for the control group. Between-group analysis revealed greater improvements in TUG Test, Barthel Index and strain elastography for the double-dose ESWT group. Generalized estimating equations analysis indicated that the double-dose ESWT group achieved superior outcomes in the TUG Test, Barthel Index, and strain elastography across various time points and groups.ConclusionsDouble-dose ESWT showed better functional improvement and elastography compared to the control group. ESWT demonstrated dose-response effectiveness for PSS of ankle-equinus.Trial registrationNCT05878223.

Acute effects of local vibration inducing tonic vibration reflex or illusion of movement on maximal wrist force production.

Local vibration (LV) mainly stimulates primary afferents (Ia) and can induce a tonic vibration reflex (TVR) and an illusion of movement. This study aimed to evaluate the effect of these two phenomena on maximal voluntary isometric contraction (MVIC) capacity. LV (80 Hz) was applied to the wrist flexor muscles in two randomized experiments for 6 min. LV conditions were adjusted to promote either TVR (visual focus on the vibrated wrist) or ILLUSION [hand hidden, visual focus on electromyographic activity of the flexor carpi radialis muscle (FCR)]. Mechanical and electromyographic (EMG) responses of the FCR and extensor carpi radialis muscles were recorded during MVIC in flexion and extension and during electrically evoked contractions at supramaximal intensity. Measurements were performed before (10 min and just before) and after (0 and 30 min) LV protocol. An increase in FCR EMG was observed during LV in the TVR condition (+340%) compared with the illusion condition (P = 0.003). In contrast, the movement illusion was greater in the ILLUSION condition (assessed through subjective scales) (P = 0.004). MVIC was reduced in flexion only after the TVR condition ([Formula: see text], all P < 0.034). Moreover, the decrease in force was correlated with the amount of TVR recorded on the FCR muscle (r = -0.64, P = 0.005). Although potentiated doublets of each muscle did not evolve differently between conditions, a decrease was observed between the first and the last measure. In conclusion, when conducting research to assess maximal strength, it is necessary to have better control and reporting of the phenomena induced during LV.NEW & NOTEWORTHY The maximal force production of the vibrated muscle is reduced after 6 min of LV only in TVR condition. Furthermore, the amount of TVR is negatively correlated with this force decrease. When measuring the effects of LV on maximal force production, it is important to control and report any phenomena induced during vibration, such as TVR or movement illusion, which can be achieved by recording EMG activity of vibrated muscle and quantifying illusion.

The Effects of cervical mobilization and clinical pilates exercises in cervicogenic headache: randomized controlled trial.

To investigate the effects of Cervical Mobilization (CM) and Clinical Pilates Exercises (CPE) in Cervigogenic Headache (CHA). The 37 patients were randomized into the 3 groups. The CM for 1st group, CPE for 2nd group and CM+CPE for 3rd group were applied 3 days/a week for 6 weeks. Pain frequency, pain intensity, number of analgesic, were recorded. The posture was measured by Posture Screen application, the cervical range of motion by the CROM device, deep neck flexor muscle endurance by the pressurized biofeedback device. Evaluations were applied 2 times as pre-post treatment. In within-group comparison a decrease in pain parameters, neck-shoulder postural deviation and an increase DNFE and CROM were observed in all groups (p<0.05). In between-group comparison pain frequency, intensity and number of analgesics were significant changes in the CM and CM+CPE groups according to CPE (respectively p<0,001, p=0,001, p=0,018). Head and shoulder angulation were significant in the CPE and CM+CPE groups according to CM (respectively p=0.009, p=0,011). It was determined that the cervical right lateral flexion range of motion and right rotation were significant changes in the CM and CM+CPE groups according to CPE (respectively p=0,026, p=0,040). DNFE were significantly increased in CM+CPE according to CM and CPE (p=0.001). This study suggests that it would be beneficial to add CM and CPE to the treatment plans of patients with CHA.

Influences of mechanical decompression using different forces on knee joint space, range of motion, and hamstring flexibility in asymptomatic subjects

INTRODUCTION: Knee joint decompression is one of the promising methods for the treatment of osteoarthritis. Yet, the most appropriate decompression force is not conclusive. OBJECTIVES: To compare the effect of different distraction force magnitudes on knee joint space, active range of motion (ROM), hamstring flexibility, and self-reported discomfort in asymptomatic subjects. METHODS AND MATERIALS: Twenty-five asymptomatic participants were recruited in this study. The dominant knee was distracted for 30 minutes in a 30° flexion position using three force magnitudes (10%, 20%, and 30% body weight (BW)). The traction forces were randomized with one week in between knee distractions. Joint space, range of motion (ROM), and hamstring flexibility were assessed before, immediately after, and 30 minutes after the distraction. The self-reported discomfort was assessed immediately after the distraction only. RESULTS: Medial joint space, ROM, and discomfort showed a significant difference between different force magnitudes post-distraction. The 20% and 30% BW force magnitudes significantly, but equally, increased joint space and ROM post distraction. The discomfort level was directly related to distraction force magnitude and the least comforting was the 30% BW force. Follow-up data was not significantly different than that for post-distraction. Hamstring muscle flexibility showed a significant. Yet, small increase after the 30% BW distraction force. CONCLUSION: Continued mechanical distraction of the knee joint using force magnitudes of 20% and 30% of body weight was effective in increasing medial joint space, active knee ROM, and hamstring flexibility in asymptomatic individuals. 20% force magnitude was more comfortable than the 30% percent.

Work-related musculoskeletal disorder and health risk behaviors in market-vendors: a mixed-methods study.

Work-related musculoskeletal disorders (WRMDs) are frequently observed among market vendors, and engaging in health risk behaviors can exacerbate these issues, leading to various health problems. Common health risk behaviors among market vendors include alcohol consumption and insufficient physical activity. However, there is currently a lack of research examining the prevalence of WRMDs and health risk behaviors among market vendors in Bangkok. Furthermore, the emerging trend of drug misuse within this group remains poorly understood. This study aims to explore the prevalence of muscle pain and flexibility issues and assess health risk behaviors, including alcohol consumption, inadequate exercise, and drug misuse, among market vendors. A mixed-method study was undertaken among 213 market vendors in Bangkok. Data collection utilized direct observation techniques, questionnaires, and muscle flexibility tests. Qualitative data were elucidated and showcased through textual descriptions and quotations. Quantitative data were analyzed using descriptive statistics to present numerical and percentage values. Qualitative findings revealed that market vendors often engage in static muscular work and maintain awkward postures due to their job characteristics and workstation setups. Quantitatively, the right arm was the most common pain region (34.7%), followed by the left leg (31.0%), right leg (30.0%), and left arm (28.6%). Additionally, 64.3% of participants showed poor muscle flexibility. The study also found that 35% of market vendors resorted to alcohol and 11.7% to drug misuse to cope with fatigue and prevent adverse symptoms. Moreover, 68.5% of participants reported no regular exercise due to lack of time. The study highlights the prevalence of musculoskeletal issues among market vendors, largely attributed to static muscular work and awkward postures dictated by their job roles and workstation arrangements. The right arm emerged as the most commonly affected area, followed by the left leg, right leg, and left arm, with significant rates of reported pain. The research also points to a notable lack of muscle flexibility in a majority of vendors and a concerning tendency towards alcohol and drug misuse as coping mechanisms for fatigue and symptom management. Furthermore, a significant portion of the vendors do not participate in regular exercise, primarily due to time constraints. These findings can be used to implement health prevention programs within the market vendor group.

Are there laterality differences in passive flexion and extension of the proximal limb joints in working Siberian Husky dogs?

Differences between left and right-side joint range of motion may affect canine locomotive ability and movement. Passive range of motion (PROM) joint measurement provides the limits that a particular joint can move in its physiological planes of motion without influence of muscle activity. To compare left and right-side flexion and extension of the glenohumeral, humeroulnar/humeroradial, coxofemoral and femorotibial joints and for laterality PROM differences. Siberian Husky dogs were selected (n = 18) of mixed gender, aged (1.4–11.8) years living and working together from a single kennel. Joint PROM was measured using goniometry, a validated, non-invasive method, by the same investigator previously tested for acceptable measurement repeatability. Dogs were conscious and placed in standing position. Triplicate measures of joint flexion and extension were taken on both sides of each dog for afore-mentioned joints. Median values of triplicate measures were computed. Paired t-tests compared laterality of joint PROM, gender, age (&lt; 6 vs. &gt; 6 years) effects. Inferential symmetry indices [SI] were calculated. There was no significant difference (p &gt; 0.05) between left and right-side flexion and extension measures for all joints. Gender had no significant effect (p &gt; 0.05) on joint flexion or extension measures for all joints. Age (&lt; 6 vs. &gt; 6 years) had a significant effect on right hip flexion (p &lt; 0.001) and for both left and right-side shoulder flexion (p &lt; 0.001); elbow flexion (p = 0.001 and p &lt; 0.001); hip extension (p = 0.02 and p &lt; 0.001) respectively. The shoulder joint showed greatest PROM asymmetry (SI = 3.63%). Bilateral PROM measures are important to consider in joint movement and assessment. These results warrant further investigation with larger cohorts of defined age groups.

Analysis of Running Techniques and Physical Factors on the Sprinter Ability of Grade V Elementary School

This study investigates the relationship between running techniques, physical factors, and the sprinting abilities of fifth-grade elementary school students. Through direct observation and measurement of students’ running techniques, as well as assessments of their physical attributes such as speed, leg muscle strength, and flexibility. This research aims to identify key factors that contribute to sprinting performance. Statistical analysis reveals a significant positive correlation between proper running techniques characterized by a forward-leaning posture, synchronized arm-leg movements, and correct foot landing and enhanced sprinting ability. Furthermore, the analysis highlights the importance of physical factors, with findings showing that students possessing greater leg muscle strength and flexibility exhibit superior sprinting capabilities. The correlation analysis underscores the strong influence of both running techniques and physical attributes on sprinting performance, indicating that improvements in these areas can lead to enhanced athletic outcomes. These findings have practical implications for the development of targeted training programs in elementary schools, emphasizing the enhancement of running techniques and physical conditioning. By focusing on structured training that incorporates muscle strengthening, flexibility improvement, and technique refinement, educators can help students maximize their athletic potential and encourage lifelong healthy habits. This research contributes to a deeper understanding of the factors influencing sprinting abilities and offers a foundation for optimizing physical education practices for young athletes.

Development of an ultrasound-based metric of muscle functional capacity for use in patients with neuromuscular disease.

Spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) are progressive neuromuscular disorders characterized by severe muscle weakness and functional decline (Pillen et al., Muscle Nerve 2008; 37(6):679-693). With new therapeutics, objective methods with increased sensitivity are needed to assess muscle function. Ultrasound imaging is a promising approach for assessing muscle fat and fibrosis in neuromuscular disorders. This study builds on prior work by combining ultrasound-based measurements of muscle size, shape, and quality, relating these measures to muscle strength, and proposing a multivariable image-based estimate of muscle function. Maximum voluntary elbow flexion torque of 36 participants (SMA, DMD, and healthy controls) was measured by hand-held dynamometry and elbow flexor muscles were imaged using ultrasound. Muscle size (cross-sectional area, maximum Feret diameter or width, and thickness), quality (echogenicity, texture anisotropy index), and cross-sectional shape (diameter ratio) were measured. Multivariable regression was used to select ultrasound measurements that predict elbow flexion torque. Significant differences were observed in muscle size (decreased), shape (thinned), and quality (decreased) with increased disease severity and compared to healthy participants. CSA (brachioradialis R2 = 0.51), maximum Feret diameter (biceps R2 = 0.49, brachioradialis R2 = 0.58) and echogenicity (brachioradialis R2 = 0.61) were most correlated with torque production. Multivariable regression models identified that muscle size (CSA, maximum Feret diameter) and quality (echogenicity) were both essential to predict elbow flexion torque (R2 = 0.65). A multivariable approach combining muscle size and quality improves strength predictions over single variable approaches. These methods present a promising avenue for the development of sensitive and functionally relevant biomarkers of neuromuscular disease.

Kinect-Based Gait Analysis System Design and Concurrent Validity in Persons with Anterolateral Shoulder Pain Syndrome, Results from a Pilot Study

As part of an investigation to detect asymmetries in gait patterns in persons with shoulder injuries, the goal of the present study was to design and validate a Kinect-based motion capture system that would enable the extraction of joint kinematics curves during gait and to compare them with the data obtained through a commercial motion capture system. The study included eight male and two female participants, all diagnosed with anterolateral shoulder pain syndrome in their right upper extremity with a minimum 18 months of disorder evolution. The participants had an average age of 31.8 ± 9.8 years, a height of 173 ± 18 cm, and a weight of 81 ± 15 kg. The gait kinematics were sampled simultaneously with the new system and the Clinical 3DMA system. Shoulder, elbow, hip, and knee kinematics were compared between systems for the pathological and non-pathological sides using repeated measures ANOVA and 1D statistical parametric mapping. For most variables, no significant difference was found between systems. Evidence of a significant difference between the newly developed system and the commercial system was found for knee flexion–extension (p &lt; 0.004, between 60 and 80% of the gait cycle), and for shoulder abduction–adduction. The good concurrent validity of the new Kinect-based motion analysis system found in this study opens promising perspectives for clinical motion tracking using an affordable and simple system.

The Association Between Femoral Nerve Tension and Hip Flexor Length

Background: Femoral nerve tension and hip flexor muscle length are critical factors in musculoskeletal health. Their relationship is particularly important in diagnosing and managing conditions like low back pain, often associated with tight hip flexors.Objective: This study aimed to explore the association between femoral nerve tension and hip flexor muscle length in individuals with acute low back pain compared to healthy controls.Methods: A correlational study was conducted with 68 participants (34 healthy controls and 34 acute low back pain patients). Data were collected using self-administered questionnaires and clinical tests, including the Prone Knee Bend Test and Modified Thomas Test. Femoral nerve tension and hip flexor length were measured using a goniometer. Data were analyzed using Pearson correlation and linear regression in SPSS version 25.Results: The Thomas Test showed a statistically significant negative correlation between femoral nerve tension and hip flexor length in Group B (-0.096, p=0.042). In the Prone Knee Bend Test, a minimal positive correlation was observed (0.007, p&gt;0.05). Cross-tabulation highlighted a significant association between test results in the control group (p=0.025).Conclusion: A significant relationship exists between femoral nerve tension and hip flexor length in individuals with acute low back pain. These findings suggest the need for targeted interventions focusing on neural and muscular components.

Single versus double fascicular transfer for brachial plexus injuries: a systematic review and meta-analysis with meta-regression.

The primary objective of this review was to assess whether double fascicular transfer has superior outcomes compared with single fascicular transfer for reanimation of elbow flexion. In total, 58 studies including 1388 patients (mean age 29 years [SD 8]) were included. Subgroup analysis comparing the severity of brachial plexus injury (C5-C6, C5-C7, C5-C8) showed no significant difference in the recovery of MRC grade 3 and 4. The aggregated mean Disabilities of Arm, Shoulder and Hand score was 38 for the single fascicular transfer group and 27 for the double fascicular transfer group. Meta-regression controlling for level of injury showed that double fascicular transfer and C5-C6 injury were significant predictors of achieving MRC grade 3, while double fascicular transfer and shorter duration of surgical delay were significant predictors of achieving MRC grade 4. When controlling for the level of injury, double fascicular transfer is associated with a greater likelihood of achieving MRC grade 3 and 4 compared to single fascicular transfer. Overall donor site morbidity was not significantly different between single fascicular transfer and double fascicular transfer.

In vivo dynamic migration of the posterior interosseous nerve across various elbow and forearm positions.

The posterior interosseous nerve (PIN) is at risk of iatrogenic nerve injury during elbow surgery when using a lateral or posterolateral approach. Results of cadaveric studies indicated that maintaining forearm pronation throughout the surgery can help move the PIN away from the surgical window. However, in vivo dynamic migration of the PIN in response to changes in the elbow and forearm position is unclear. This study aimed to clarify the in vivo dynamic migration pattern of the PIN in response to changes in the elbow and forearm position using ultrasound imaging. This study included 43 upper extremities of 22 healthy volunteers (16 females; mean age, 29 years). Using ultrasound imaging, we measured the shortest distance from the radial head (RH) to the point where the PIN crossed the lateral aspect of the radial axis in six positions of the elbow and forearm: 90° forearm supination, 90° pronation, and neutral forearm position, each at 135° of elbow flexion and 0° of elbow extension. The RH-to-nerve distance was greater during elbow extension than during elbow flexion regardless of the forearm position. However, the maximum migration distance was 3.5 mm when transitioning from elbow extension and forearm pronation (25.1 mm) to elbow flexion and forearm supination (21.6 mm). Although forearm pronation may help move the PIN away from the surgical window, care should be taken not to injure the nerve when performing elbow surgery using a lateral or posterolateral approach. Level of evidence: Level III.

Applying 3D Models of Giant Salamanders to Explore Form-Function Relationships in Early Digit-Bearing Tetrapods.

Extant salamanders are used as modern analogs of early digit-bearing tetrapods due to general similarities in morphology and ecology, but the study species have been primarily terrestrial and relatively smaller when the earliest digit-bearing tetrapods were aquatic and an order of magnitude larger. Thus, we created a 3D computational model of underwater walking in extant Japanese giant salamanders (Andrias japonicus) using 3D photogrammetry and open-access graphics software (Blender) to broaden the range of testable hypotheses about the incipient stages of terrestrial locomotion. Our 3D model and software protocol represent the initial stages of an open-access pipeline that could serve as a "one-stop-shop" for studying locomotor function, from creating 3D models to analyzing the mechanics of locomotor gaits. While other pipelines generally require multiple software programs to accomplish the different steps in creating and analyzing computational models of locomotion, our protocol is built entirely within Blender and fully customizable with its Python scripting so users can devote more time to creating and analyzing models instead of navigating the learning curves of several software programs. The main value of our approach is that key kinematic variables (e.g. speed, stride length, and elbow flexion) can be easily altered on the 3D model, allowing scientists to test hypotheses about locomotor function and conduct manipulative experiments (e.g. lengthening bones) that are difficult to perform in vivo. The accurate 3D meshes (and animations) generated through photogrammetry also provide exciting opportunities to expand the abundance and diversity of 3D digital animals available for researchers, educators, artists, conservation biologists, etc. to maximize societal impacts.

Test–Retest Reliability of Concentric and Eccentric Muscle Strength in Knee Flexion–Extension Controlled by Functional Electromechanical Dynamometry in Female Soccer

In the field of sports performance, sports medicine, and physical rehabilitation, there is a great interest in the development of protocols and reliable techniques and instruments for the evaluation of strength produced by athletes. In the last ten years, women’s football has increased its popularity and participation in numerous countries, which has contributed to players developing more professionally and requiring more specific muscle strength training to improve their performance. The aim of this study was to analyze the absolute and relative test–retest reliabilities of peak muscle strength in knee flexion (FLE) and extension (EXT) controlled using a functional electromechanical dynamometer (FEMD) in a group of seventeen professional female soccer players (age = 18.64 ± 0.62 years; weight = 54.72 ± 7.03 kg; height = 1.58 ± 0.04 m; BMI = 21.62 ± 2.70 kg/m2). Peak muscle strength was measured with knee flexion (FLE) and extension (EXT) movements at a speed of 0.4 m·s−1 unilaterally in a concentric phase (CON) and an eccentric phase (ECC). No significant mean differences were found in the test–retest analysis (p &gt; 0.05; effect size &lt; 0.14), and high reliability was reported for peak muscle strength assessments in both the CON (ICC) = 0.90–0.95) and the ECC (ICC = 0.85–0.97). Furthermore, stable repeatability was presented for extension in the CON (CV = 7.39–9.91%) and ECC (CV = 8.65–13.64). The main findings of this study show that peak muscle strength in knee flexion and extension in CON and ECC is a measure with acceptable absolute reliability and extremely high relative reliability using the FEMD in professional female soccer players.

Flexible AgNW/PDMS nanocomposite for strain and pressure sensing

This study presents the fabrication and characterization of an ultra-thin (<1 mm) piezoresistive sensor based on a silver nanowire (AgNW) and polydimethylsiloxane (PDMS) nanocomposite, capable of simultaneous strain and pressure sensing. The sensor exhibits high sensitivity, detecting strains as low as 0.5 % with a range of up to 40 %, demonstrates frequency responsiveness from 0.5 to 3 Hz, and maintains functionality over 1000 cycles. The sensor’s performance was evaluated through cyclic tensile and compressive tests. We hypothesize that the compression sensing mechanism is a consequence of the Poisson effect in the PDMS substrate, where transverse compression induces axial strains parallel to the AgNW network, causing disconnections within the nanowire matrix. The sensor’s versatility was demonstrated through various biofeedback applications, including finger bending, applied pressure, calf raises, and elbow flexion. With its thin profile and dual-mode sensing capability, this AgNW/PDMS nanocomposite sensor shows promise for biomechanics, sports science, and healthcare monitoring applications.

Intrinsic Risk Factors for Noncontact Anterior Cruciate Ligament Injury in Young Female Soccer Players: A Prospective Cohort Study.

Previous studies have attempted to determine prognostic factors for predicting the occurrence of noncontact anterior cruciate ligament (ACL) injuries. However, studies on risk factors for noncontact ACL injuries in Asian female soccer players are limited. To identify intrinsic risk factors for noncontact ACL injuries among young female Asian soccer players. Cohort study; Level of evidence, 2. This study evaluated 145 female Japanese soccer players for potential risk factors for noncontact ACL injury during the preseason medical assessment. In total, 25 variables were examined-including anthropometric data, joint range of motion, muscle flexibility, muscle strength, and balance measurements. Participants were monitored throughout a single season for noncontact ACL injuries diagnosed by physicians. Noncontact ACL injuries occurred in 13 knees of 13 players (9%). Lower hamstring-to-quadriceps ratio (0.44 ± 0.07 vs 0.50 ± 0.10; P = .04), greater knee extension muscle strength (3.2 ± 0.5 vs 2.7 ± 0.5 N·m/kg; P < .01), and longer playing experience (10.8 ± 3 vs 8.1 ± 4.2 years; P = .02) were significantly associated with new-onset noncontact ACL injuries in young female soccer players. No statistically significant between-group differences were found for any other variables. New-onset noncontact ACL injury in young female soccer players was significantly associated with lower hamstring-to-quadriceps ratio, greater knee extension muscle strength, and longer soccer experience. These findings will help develop strategies for preventing noncontact ACL injuries among female soccer players.

Contributions to forearm desaturation during transient ischemia in healthy adult males and females across the lifespan.

This study investigated skeletal muscle tissue oxygenation (StO2) desaturation in males and females across the adult lifespan. One-hundred-two individuals (51 females) of 41 young, 34 midlife, and 27 older adults completed a vascular occlusion test with near-infrared spectroscopy (NIRS+VOT). This included five minutes of arterial occlusion, inducing transient ischemia in the forearm flexor muscle group while recording StO2. The magnitude of desaturation (StO2mag) was quantified as the difference between baseline StO2 and the minimum StO2 value observed during ischemia. The rate of desaturation was also examined. Forearm adipose tissue thickness (ATT), forearm lean mass, and handgrip muscular strength were measured. A p ≤ 0.05 was considered significant. Two-way between factor ANOVAs indicated that males exhibited significantly (p<0.001) less ATT than females (collapsed across age) and that forearm lean mass (p<0.001) and muscular strength (p<0.001) decreased across the lifespan independent of sex. Bivariate analyses revealed significant (p<0.05) associations for sex, age, ATT, forearm lean mass, and muscular strength with the desaturation metrics. The ATT values demonstrated the strongest relations with StO2mag and desaturation rate (r = -0.620 and 0.618). Using a model comparison approach, ATT plus age offered the best predictive power for StO2mag and desaturation rate (R2 = 0.456 and 0.438) such that the inclusion of sex did not improve the models. These findings suggested differences in desaturation were primarily explained by variations in ATT and, to a lesser extent, age, but biological sex had no meaningful effect. Future studies must determine what other factors influence desaturation during ischemia.