Electromyographic Activity of selected Trunk, Core, and Thigh Muscles in commonly used Exercises for ACL Rehabilitation

Purpose: Most of rehabilitation programmes for Anterior Cruciate Ligament (ACL) injury focus on quadriceps-hamstrings activation imbalances and less is known about kinetically linked muscles. Study investigated electromyographic activity of selected trunk, core, and thigh muscles during common rehabilitation exercises for ACL injury. Subjects and Methods: Twelve active female volunteers participated in this cross-sectional laboratory study. Surface EMG was used to compare activation of eight trunk, hip/core, and lower limb muscles: Erector Spinae (ES), Rectus Abdominis (RA), Gluteus Maximus (GM), Vastus Lateralis (VL), Rectus Femoris (RF), Vastus Medialis (VM), Biceps Femoris (BF), and Semitendinosus (ST) during Forward Lunge, Double Leg Raise, Glute Bridge, Sit-Up, and Squat. Results: Forward lunge produced significantly higher activation in the VM (61.1±19.4), VL (59.2±12.9), and RF (32.0±2.6). Double leg raise generated highest activity in the RF (26.6±2.8) and RA (43.3±4.4); and Glute Bridge in the GM (44.5±19.0) and BF (22.4±4.3). Sit-up produced the highest activation in the RF (36.6±4.7) followed by RA (18.9±3.8). Squat produced a higher activation in VL (55.0±12.9), VM (51.5±18.2), and ES (40.4±18.3). Conclusion: Study provide further evidence for developing training programmes for ACL injury prevention and rehabilitation. A combination of exercises to reinstate quadriceps-hamstrings activation balance and enhance core stability is recommended

Electromyographic Assessment of Forearm Muscle Function in Tennis Players With and Without Lateral Epicondylitis

"There is no consensus about the main aetiology of Lateral Epicondylitis (LE) or Tennis Elbow. While electromyographic assessment of alterations in neuromuscular control and activation patterns of forearm muscles has received increasing interest as potential intrinsic factors in non-tennis players, there has been insufficient attention in tennis players. The purpose of present review was to search the literature for the electromyographic studies of forearm muscles in tennis players in order to 1) identify related implications for LE, 2) highlight key technical and methodological shortcomings, and 3) suggest potential pathways for future research. An electronic search of PubMed, Scopus, Web of Science, and Google Scholars (1980 to October 2014) was conducted. Titles, abstracts, and full-text articles were screened to identify “peer-reviewed” studies specifically looking into “electromyographic assessment of forearm muscles” in “tennis players”. After screening 104 articles, 13 original articles were considered in the main review involving a total of 216 participants (78% male, 22% female). There were indications of increased extensor activity in all tennis strokes and less experiences single-handed players, however with insufficient evidence to support their relationship with the development of LE. Studies varied widely in study population, sample size, gender, level of tennis skills, electrode type, forearm muscles studied, EMG recording protocol, EMG normalisation, and reported parameters. As a result, it was not possible to present combined results of existing studies and draw concrete conclusions in terms of clinical implications of findings. There is a need for establishment of specific guidelines and recommendations for EMG assessment of forearm musculature in terms of electrode and muscle selection. Further studies of both healthy controls and tennis players suffering from TE with adequate sample sizes and well-defined demographics are warranted.

Electromyographic Analysis of Shoulder Girdle Muscles during Common Internal Rotation Exercises

Background: High level throwing performance requires the development of effective muscle activation within shoulder girdle muscles particularly during forceful internal rotation (IR) motions. Study Design: Controlled Laboratory Descriptive Study Purpose: To investigate activation pattern of 16 shoulder girdle muscles/muscle sub-regions during three common shoulder IR exercises. Method: EMG was recorded in 30 healthy subjects from 16 shoulder girdle muscles/muscle sub-regions (surface electrode: anterior, middle and posterior deltoid, upper, middle and lower trapezius, serratus anterior, teres major, upper and lower latissimus dorsi, upper and lower pectoralis major; fine wire electrodes: supraspinatus, infraspinatus, subscapularis and rhomboid major) using a telemetric EMG system. Three IR exercises (standing IR at 0o and 90o of Abduction, and IR at Zero-Position) were studied. EMG amplitudes were normalized to EMGmax (EMG at maximal IR force in a standard position) and compared using one-way repeated-measures analysis of variance (ANOVA). Results: There were significant differences in muscles’ activation across IR exercises (p<0.05–p<0.001). Rotator cuff and deltoid muscles were highly activated during IR at 90° of Abduction. Latissimus dorsi exhibited markedly higher activation during IR at Zero-Position. While upper trapezius had the highest activation during IR at Zero-Position, middle and lower trapezius were activated at highest during IR at 90o of Abduction. The highest activation of serratus anterior and rhomboid major occurred in IR at Zero-Position and IR at 90o of Abduction, respectively. Conclusions: Studied exercises have the potential to effectively activate glenohumeral and scapular muscles involved in throwing motions. Results provide further evidence for developing rehabilitation, injury prevention, and training strategies

Pain, Functional Disability, Psychological Status, and Health-Related Quality of Life in Patients with Subacromial Impingement Syndrome

Background Subacromial impingement syndrome (SAIS) is the comments painful shoulder condition leading to considerable functional loss. Considering numerous existing conservative and surgical interventions for SAIS, the use of optimal patient-centred outcome measures is essential. Study assessed various generic and shoulder-specific outcome measures in patients and healthy controls to provide baseline data and facilitate the development of evidence-based interventions. Methods A total of 75 participants including 39 patients and 36 healthy controls were evaluated and compared by a battery of validated outcome tools: McGill Pain Questionnaire, Oxford Shoulder Score, Constant Murley Score, The Disability of the Arm, Shoulder and Hand, Upper Limb Function Index, Functional Impairment Test–Hand and Neck/Shoulder/Arm, Hospital Anxiety and Depression Scale, Short-Form Health Survey, and shoulder muscle strength. Results All selected measures showed significant differences in the pain experience, upper limb functional capacity, psychological status (anxiety and depression), and health-related quality of life between SAIS patients and healthy controls in both female and male participant groups (p<0.05 - p<0.001). Conclusion The use of an array of patient-centred upper limb regional/joint-specific pain and functional measures combined with psychological status and quality of life tools is recommended for the evidence-based assessment of intervention outcome in patients with SAIS

Electromyographic assessment of muscle fatigue in massive rotator cuff tear

Shoulder muscle fatigue has not been assessed in massive rotator cuff tear (MRCT). This study used EMG to measure fatigability of 13 shoulder muscles in 14 healthy controls and 11 patients with MRCT. A hand grip protocol was applied to minimise artifacts due to pain experience during measurement. The fatigue index (median frequency slope) was significantly non-zero (negative) for anterior, middle, and posterior parts of deltoid, supraspinatus and subscapularis muscles in the controls, and for anterior, middle, and posterior parts of deltoid, and pectoralis major in patients (p ≤ 0.001). Fatigue was significantly greater in patients compared to the controls for anterior and middle parts of deltoid and pectoralis major (p ≤ 0.001). A submaximal grip task provided a feasible way to assess shoulder muscle fatigue in MRCT patients, however with some limitations. The results suggest increased activation of deltoid is required to compensate for lost supraspinatus abduction torque. Increased pectoralis major fatigue in patients (adduction torque) likely reflected strategy to stabilise the humeral head against superior subluxing force of the deltoid. Considering physiotherapy as a primary or adjunct intervention for the management of MRCT, the findings of this study generate a base for future clinical studies aiming at the development of evidence-based protocol

POSTURAL ALTERATIONS IN PATIENTS WITH SUBACROMIAL IMPINGEMENT SYNDROME.

BackgroundAn aberrant upper body posture has been proposed as one of the etiological factors contributing to the development of subacromial impingement syndrome (SAIS). Clinicians have translated this supposition into assessment and rehabilitation programs despite insufficient and conflicting evidence to support this approach.PurposeThe purpose of this study was to compare several postural variables between the SAIS patients and asymptomatic healthy controls.Study designCase-Control Study.MethodsA total of 75 participants including 39 patients (20 females; 19 males) and 36 healthy controls (15 females; 21 males) participated in the study. Study evaluated several postural variables including forward head posture (FHP), forward shoulder posture (FSP), thoracic kyphosis index (TKI), scapular index (SI), normalized scapular protraction (NSP), and the lateral scapular slide test (LSST). The variables were compared between patient and control groups according to sex.ResultsSignificant differences were observed in the female patients compared to asymptomatic controls for the FHP (49.38 + 9.6o vs 55.5o+8.38, p=0.03), FSP (45.58 + 10.1o vs 53.68 + 7.08, p=0.02), and LSST in third position (10.2 + 2.1cm vs 11.5 + 0.7cm, p=0.01). Male patients showed a significant difference only in the FSP compared to controls (61.9o+9.4o vs 49.78 + 9.28, pConclusionsWhile inadequate data on the relationship between dysfunctional posture and SAIS has led to broad variations in current rehabilitation strategies, the results of the present study revealed different patterns of postural aberrations in female and male patients with SAIS. This clarifies the need to develop individualized or sex-specific approaches for assessing posture in men and women with SAIS and rehabilitation programs based on the assessment results.Level of evidence3b

Subacromial Impingement Syndrome: An Electromyographic Study of Shoulder Girdle Muscle Fatigue

Muscle fatigue affecting glenohumeral and/or scapular muscles is suggested as one of the 25 contributing factors to the development of subacromial impingement syndrome (SAIS). 26 Nonetheless, the fatigability of shoulder girdle muscles in association with the pathomechanics 27 of SAIS has not been reported. This study aimed to measure and compare fatigue progression 28 within the shoulder girdle musculature of patients and healthy controls. 75 participants 29 including 39 patients (20 females; 19 males) and 36 healthy controls (15 females; 21 males) 30 participated in the study. Study evaluated the progression of muscle fatigue in 15 shoulder 31 girdle muscles by means of surface and fine-wire EMG during submaximal contraction of four 32 distinct movements (abduction, flexion, internal and external rotation). Shoulder strength, 33 subjective pain experience (McGill Pain Questionnaire), and psychological status (Hospital 34 Anxiety and Depression Scale) were also assessed. The results were compared between patient 35 and control groups according to the gender. Despite marked fatigue observed in the majority 36 of muscles particularly during flexion and abduction at 90°, overall results indicated a lower 37 tendency of fatigue progression in the impingement group across the tests (0.05< p <0.05). 38 Shoulder Strength, pain experience, and psychological status were significantly different 39 between the two groups (P<0.05). Lower tendency to fatigue progression in the impingement 40 group can be attributed to the presence of fear avoidance and pain-related muscle inhibition, 41 which in turn lead to adaptations in motor programme to reduce muscle recruitment and 42 activation. The significantly higher levels of pain experience and anxiety/depression in the 43 impingement group further support this proposition

A2 milk enhances dynamic muscle function following repeated sprint exercise, a possible ergogenic aid for a1-protein intolerant athletes?

�� 2019 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher���s website: https://doi.org/10.3390/nu9020094Hyperaminoacidemia following ingestion of cows-milk may stimulate muscle anabolism and attenuate exercise-induced muscle damage (EIMD). However, as dairy-intolerant athletes do not obtain the reported benefits from milk-based products, A2 milk may offer a suitable alternative as it lacks the A1-protein. This study aimed to determine the effect of A2 milk on recovery from a sports-specific muscle damage model. Twenty-one male team sport players were allocated to three independent groups: A2 milk (n = 7), regular milk (n = 7), and placebo (PLA) (n = 7). Immediately following muscle-damaging exercise, participants consumed either A2 milk, regular milk or PLA (500 mL each). Visual analogue scale (muscle soreness), maximal voluntary isometric contraction (MVIC), countermovement jump (CMJ) and 20-m sprint were measured prior to and 24, 48, and 72 h post EIMD. At 48 h post-EIMD, CMJ and 20-m sprint recovered quicker in A2 (33.4 �� 6.6 and 3.3 �� 0.1, respectively) and regular milk (33.1 �� 7.1 and 3.3 �� 0.3, respectively) vs. PLA (29.2 �� 3.6 and 3.6 �� 0.3, respectively) (p < 0.05). Relative to baseline, decrements in 48 h CMJ and 20-m sprint were minimised in A2 (by 7.2 and 5.1%, respectively) and regular milk (by 6.3 and 5.2%, respectively) vs. PLA. There was a trend for milk treatments to attenuate decrements in MVIC, however statistical significance was not reached (p = 0.069). Milk treatments had no apparent effect on muscle soreness (p = 0.152). Following muscle-damaging exercise, ingestion of 500 mL of A2 or regular milk can limit decrements in dynamic muscle function in male athletes, thus hastening recovery and improving subsequent performance. The findings propose A2 milk as an ergogenic aid following EIMD, and may offer an alternative to athletes intolerant to the A1 protein.Published versio

Management of work-relevant upper limb disorders: a review

Background Upper limb disorders (ULDs) are clinically challenging and responsible for considerable work loss. There is a need to determine effective approaches for their management. Aim To determine evidence-based management strategies for work-relevant ULDs and explore whether a biopsychosocial approach is appropriate. Methods Literature review using a best evidence synthesis. Data from articles identified through systematic searching of electronic databases and citation tracking were extracted into evidence tables. The information was synthesized into high-level evidence statements, which were ordered into themes covering classification/diagnosis, epidemiology, associations/risks and management/treatment, focusing on return to work or work retention and taking account of distinctions between non-specific complaints and specific diagnoses. Results Neither biomedical treatment nor ergonomic workplace interventions alone offer an optimal solution; rather, multimodal interventions show considerable promise, particularly for occupational outcomes. Early return to work, or work retention, is an important goal for most cases and may be facilitated, where necessary, by transitional work arrangements. The emergent evidence indicates that successful management strategies require all the players to be onside and acting in a coordinated fashion; this requires engaging employers and workers to participate. Conclusions The biopsychosocial model applies: biological considerations should not be ignored, but psychosocial factors are more influential for occupational outcomes. Implementation of interventions that address the full range of psychosocial issues will require a cultural shift in the way the relationship between upper limb complaints and work is conceived and handled. Dissemination of evidence-based messages can contribute to the needed cultural shift

A randomized controlled trial of a group-based gaze training intervention for children with Developmental Coordination Disorder

The aim of this study was to integrate a gaze training intervention (i.e., quiet eye training; QET) that has been shown to improve the throwing and catching skill of children with Developmental Coordination Disorder (DCD), within an approach (i.e., group therapy) that might alleviate the negative psychosocial impact of these motor skill deficits. Twenty-one children with DCD were split into either QET (8 male 3 female, mean age of 8.6 years (SD = 1.04) or technical training (TT) groups (7 male 3 female, mean age of 8.6 years (SD = 1.84). The TT group were given movement-related instructions via video, relating to the throw and catch phases, while the QET group were also taught to fixate a target location on the wall prior to the throw (QE1) and to track the ball prior to the catch (QE2). Each group partook in a 4-week, group therapy intervention and measurements of QE duration and catching performance were taken before and after training, and at a 6-week delayed retention test. Parental feedback on psychosocial and motor skill outcomes was provided at delayed retention. Children improved their gaze control and catching coordination following QET, compared to TT. Mediation analysis showed that a longer QE aiming duration (QE1) predicted an earlier onset of tracking the ball prior to catching (QE2) which predicted catching success. Parents reported enhanced perceptions of their child’s catching ability and general coordination in the QET group compared to the TT group. All parents reported improvements in their child’s confidence, social skills and predilection for physical activity following the trial. The findings offer initial support for an intervention that practitioners could apply to address deficits in the motor and psychosocial skills of children with DCD