Therapeutic Photobiomodulation Before Strenuous Exercise Attenuates Shoulder Muscle Fatigue.

Context: Photobiomodulation therapy (PBMT) applied as a preconditioning treatment before exercise has been shown to attenuate fatigue and improve skeletal muscle contractile function during high-intensity resistance exercise. Practical implications for preconditioning muscles with PBMT before fatiguing exercise include a safe and noninvasive means to enhance performance and reduce the risk of musculoskeletal injury.

Objective: To examine the muscle fatigue-attenuating effects of PBMT on performance of the shoulder external-rotator muscle group when applied as a preconditioning treatment before high-intensity, high-volume resistance exercise.

Circulating Inflammatory Biomarkers Predict Pain Change Following Exercise-Induced Shoulder Injury: Findings From the Biopsychosocial Influence on Shoulder Pain Preclinical Trial.

Shoulder pain is a highly prevalent musculoskeletal condition that frequently leads to suboptimal clinical outcomes. This study tested the extent to which circulating inflammatory biomarkers are associated with reports of shoulder pain and upper-extremity disability for a high-risk genetic by psychological subgroup (catechol-O-methyltransferase [COMT] variation by pain catastrophizing [PCS]). Pain-free adults meeting high-risk COMT × PCS subgroup criteria completed an exercise-induced muscle injury protocol.

Biopsychosocial influence on shoulder pain: results from a randomized preclinical trial of exercise-induced muscle injury.

Prior cohort studies validated that a subgroup defined by a specific COMT genotype and pain catastrophizing is at increased risk for heightened responses to exercise-induced or surgically induced shoulder pain. In this clinical trial, we used our preclinical model of exercise-induced muscle injury and pain to test the efficacy of interventions matched to characteristics of this high-risk subgroup (ie, personalized medicine approach). Potential participants provided informed consent to be screened for eligibility based on subgroup membership and then, as appropriate, were enrolled into the trial.

Sensory and Psychological Factors Predict Exercise-Induced Shoulder Injury Responses in a High-Risk Phenotype Cohort.

Our prior studies identified a high-risk phenotype (ie, high pain sensitivity variant of the catechol-O-methyltransferase gene (Single Nucleotide Polymorphism [SNP] rs6269) and pain catastrophizing scores) for shoulder pain. The current study identified sensory and psychological predictors of heightened pain responses following exercise-induced shoulder injury. Healthy participants (N = 131) with the SNP rs6269 catechol-O-methyltransferase gene and Pain Catastrophizing Scale scores ≥5 underwent baseline sensory and psychological testing followed by an established shoulder fatigue protocol, to induce muscle injury.

Plasma Concentrations of Select Inflammatory Cytokines Predicts Pain Intensity 48 Hours Post-Shoulder Muscle Injury.

Objectives: The relationship between elevated inflammatory cytokine levels and peak pain intensity following acute musculoskeletal injury has not been fully elucidated in high risk subgroups. Identifying the role that these cytokines have on pain responses may help with developing tailored therapeutic approaches.

Methods: Data were collected from 54 participants who were vulnerable to a robust pain response and delayed recovery following musculoskeletal injury.

Pitching shoulder passive flexibility: torque-angle analysis for external rotation and internal rotation.

In this study, a custom device was developed to analyse the pitching shoulder's external rotation (ER) and internal rotation (IR) passive flexibility. We analysed three novel measures: the resistance onset angle (ROA = angle where the shoulder begins stretching), rotational stiffness, and torque at the end range of motion (ROM). The purpose was to conduct a bilateral analysis to determine if there are significant differences between the throwing and non-throwing shoulder.

Genetic and psychological factors interact to predict physical impairment phenotypes following exercise-induced shoulder injury.

Background: We investigated interactions between genetic and psychological factors in predicting shoulder impairment phenotypes. We hypothesized that pro-inflammatory genes would display stronger relationships compared with pain-related genes when combined with psychological factors for predicting phenotypic changes.

Subjects And Methods: Altogether, 190 participants completed a 5-day experimental protocol.

Motoneuron Function Does not Change Following Whole-Body Vibration in Individuals With Chronic Ankle Instability.

Context: Following a lateral ankle sprain, ∼40% of individuals develop chronic ankle instability (CAI), characterized by recurrent injury and sensations of giving way. Deafferentation due to mechanoreceptor damage postinjury is suggested to contribute to arthrogenic muscle inhibition (AMI). Whole-body vibration (WBV) has the potential to address the neurophysiologic deficits accompanied by CAI and, therefore, possibly prevent reinjury.

Developing reliable measures of the passive torque-angle relationship for shoulder internal and external rotation: Implications for overhead athletics.

Objectives: 1) Thoroughly assess shoulder flexibility by establishing the passive torque-angle relationship for internal and external rotation with the arm in an overhead athletics position (abducted 90°) and 2) test the reliability of four passive torque-angle measures.

Design: Reliability study.

Setting: Data were collected in a university biomechanics laboratory.

Prolonged Reduction in Shoulder Strength after Transcutaneous Electrical Nerve Stimulation Treatment of Exercise-Induced Acute Muscle Pain.

Objectives: Transcutaneous electrical nerve stimulation (TENS) is commonly used for reducing musculoskeletal pain to improve function. However, peripheral nerve stimulation using TENS can alter muscle motor output. Few studies examine motor outcomes following TENS in a human pain model.

Biopsychosocial influence on shoulder pain: Rationale and protocol for a pre-clinical trial.

Background: Chronic musculoskeletal pain conditions are a prevalent and disabling problem. Preventing chronic musculoskeletal pain requires multifactorial treatment approaches that address its complex etiology. Prior cohort studies identified a high risk subgroup comprised of variation in COMT genotype and pain catastrophizing.

Expectancy Reduces Symptoms but not Functional Impairment Following Exercise-induced Musculoskeletal Injury.

Objectives: To quantify the extent to which the participant-provider interaction influences the response to sham treatment following exercised-induced acute musculoskeletal pain.

Materials And Methods: In total, 40 participants between the ages of 18 and 35 volunteered for the study. Participants came to the laboratory for 3 test sessions 48-hour apart (day 1, 3, and 5).

Photobiomodulation delays the onset of skeletal muscle fatigue in a dose-dependent manner.

Photobiomodulation (PBM) therapy has been implicated as an effective ergogenic aid to delay the onset of muscle fatigue. The purpose of this study was to examine the dose-response ergogenic properties of PBM therapy and its ability to prolong time to task failure by enhancing muscle activity and delaying the onset of muscle fatigue using a static positioning task. Nine participants (24.

Range of motion as a predictor of clinical shoulder pain during recovery from delayed-onset muscle soreness.

Context: Athletic trainers use clinical pain and range of motion (ROM) to gauge recovery after musculoskeletal injury. Limited evidence to date suggests which shoulder ROM measures can predict symptomatic relief and functional recovery after delayed-onset muscle soreness (DOMS).

Objective: To determine whether shoulder passive internal rotation, passive external rotation, active abduction, and active flexion and evoked pain with abduction are associated with resting pain experienced after exercise-induced DOMS.

Biopsychosocial influence on shoulder pain: risk subgroups translated across preclinical and clinical prospective cohorts.

Tailored treatment based on individual risk factors is an area with promise to improve options for pain relief. Musculoskeletal pain has a biopsychosocial nature, and multiple factors should be considered when determining risk for chronic pain. This study investigated whether subgroups comprised genetic and psychological factors predicted outcomes in preclinical and clinical models of shoulder pain.

Near-infrared light therapy to attenuate strength loss after strenuous resistance exercise.

Context: Near-infrared (NIR) light therapy is purported to act as an ergogenic aid by enhancing the contractile function of skeletal muscle. Improving muscle function is a new avenue for research in the area of laser therapy; however, very few researchers have examined the ergogenic effects of NIR light therapy and the influence it may have on the recovery process during rehabilitation.

Objective: To evaluate the ergogenic effect of NIR light therapy on skeletal muscle function.

Suprathreshold heat pain response predicts activity-related pain, but not rest-related pain, in an exercise-induced injury model.

Exercise-induced injury models are advantageous for studying pain since the onset of pain is controlled and both pre-injury and post-injury factors can be utilized as explanatory variables or predictors. In these studies, rest-related pain is often considered the primary dependent variable or outcome, as opposed to a measure of activity-related pain. Additionally, few studies include pain sensitivity measures as predictors.

Inflammatory genes and psychological factors predict induced shoulder pain phenotype.

Purpose: The pain experience has multiple influences, but little is known about how specific biological and psychological factors interact to influence pain responses. The current study investigated the combined influences of genetic (pro-inflammatory) and psychological factors on several preclinical shoulder pain phenotypes.

Methods: An exercise-induced shoulder injury model was used, and a priori selected genetic (IL1B, TNF/LTA region, and IL6 single nucleotide polymorphisms (SNP)) and psychological (anxiety, depression symptoms, pain catastrophizing, fear of pain, and kinesiophobia) factors were included as the predictors of interest.

Biopsychosocial influence on exercise-induced injury: genetic and psychological combinations are predictive of shoulder pain phenotypes.

Unlabelled: Chronic pain is influenced by biological, psychological, social, and cultural factors. The current study investigated potential roles for combinations of genetic and psychological factors in the development and/or maintenance of chronic musculoskeletal pain. An exercise-induced shoulder injury model was used, and a priori selected genetic (ADRB2, COMT, OPRM1, AVPR1 A, GCH1, and KCNS1) and psychological (anxiety, depressive symptoms, pain catastrophizing, fear of pain, and kinesiophobia) factors were included as predictors.

Effect of near-infrared light exposure on mitochondrial signaling in C2C12 muscle cells.

Near-infrared (NIR) light is a complementary therapy used to treat musculoskeletal injuries but the underlying mechanisms are unclear. Acute NIR light treatment (~800-950 nm; 22.8 J/cm(2)) induced a dose-dependent increase in mitochondrial signaling (AMPK, p38 MAPK) in differentiated muscle cells.

Perceptions of wellness and burnout among certified athletic trainers: sex differences.

Context: Athletic trainers are exposed to various stressors, increasing the potential for burnout and decreasing perceived wellness. Burnout and decreased perceived wellness can result from many factors: years of experience, hours per week worked, or decreased levels of physical activity. Another factor that accounts for a portion of the variance is sex differences.

Does phototherapy enhance skeletal muscle contractile function and postexercise recovery? A systematic review.

Context: Recently, researchers have shown that phototherapy administered to skeletal muscle immediately before resistance exercise can enhance contractile function, prevent exercise-induced cell damage, and improve postexercise recovery of strength and function.

Objective: To critically evaluate original research addressing the ability of phototherapeutic devices, such as lasers and light-emitting diodes (LEDs), to enhance skeletal muscle contractile function, reduce exercise-induced muscle fatigue, and facilitate postexercise recovery.

Data Sources: We searched the electronic databases PubMed, SPORTDiscus, Web of Science, Scopus, and Rehabilitation & Physical Medicine without date limitations for the following key words: laser therapy, phototherapy, fatigue, exercise, circulation, microcirculation, and photobiomodulation.

Oral consumption of electrokinetically modified water attenuates muscle damage and improves postexercise recovery.

The purpose of this study was to assess the effects of consuming electrokinetically modified water (EMW) on attenuating muscle damage and improving functional recovery following a single bout of isokinetic resistance exercise. Subjects were randomly assigned to an EMW (n = 20) or a placebo control (n = 20) group. Subjects consumed EMW or placebo water daily for 23 days.

The effects of low-level laser therapy in a rat model of intestinal ischemia-reperfusion injury.

Background And Objective: To investigate the effects of low-level laser therapy applied to the serosal surface of the rat jejunum following ischemia and reperfusion.

Materials And Methods: Ninety-six male Sprague-Dawley rats were assigned to 15 groups and anesthetized. Small intestinal ischemia was induced by clamping the superior mesenteric artery for 60 minutes.

17β-Hydroxyestra-4,9,11-trien-3-one (Trenbolone) preserves bone mineral density in skeletally mature orchiectomized rats without prostate enlargement.

Testosterone enanthate (TE) administration attenuates bone loss in orchiectomized (ORX) rats. However, testosterone administration may increase risk for prostate/lower urinary tract related adverse events and polycythemia in humans. Trenbolone enanthate (TREN) is a synthetic testosterone analogue that preserves bone mineral density (BMD) and results in less prostate enlargement than testosterone in young ORX rodents.