The effects of cervical muscle fatigue on balance - A study with elite amateur rugby league players

Neck muscle fatigue has been shown to alter an individual’s balance in a similar way to that reported in subjects suffering from neck pain or subjects that have suffered a neck injury. The main purpose of the present study was to quantify the effects of neck fatigue on neck muscle electromyography (EMG) activity, balance, perceived fatigue and perceived stability. Forty four elite amateur rugby league players resisted with their neck muscles approximately 35% maximum voluntary isometric contraction (MVIC) force for 15 minutes in eight different directions. Sway velocity and surface electromyography were measured. Questionnaires were used to record perceived effort and stability. Repeated measures ANOVA showed that after 15 minutes isometric contraction, significant changes were seen in sway velocity, perceived sway and EMG median frequency. There were no differences in perceived efforts. The changes in sway velocity and median frequency were more pronounced after extension and right and left posterior oblique contractions but there was no significant difference in sway velocity after contraction in the right lateral flexion, right anterior oblique and left anterior oblique direction of contraction. All the subjects showed oriented whole-body leaning in the plane of the contraction. The experiment produced significantly altered and perceived altered balance in this group of physically fit individuals. The results may contribute to our understanding of normal functional capacities of athletes and will provide a basis for further investigation in healthy non-athletes and participants that have suffered neck injuries. This may ultimately help develop accurate and valid rehabilitation outcome measures

Effects of cervical muscle fatigue on the perception of the subjective vertical and horizontal

Introduction: Cervical functional capacity outcome measures that are simple and reliable are urgently needed in order permit accurate assessment/reassessment during treatments and rehabilitation. Induced neck muscle fatigue has been shown to alter functional capacities such as balance and kinaesthetic sense in the standing posture. The Rod and Frame Test has also shown promise as a method of assessing the effects of chronic neck pain and injury, but currently only in the sitting position. The objectives of this project were therefore 1) to validate the computerised rod and frame test in the standing posture, and 2) to measure the effects that different cervical muscle fatigue protocol would have on the assessment of the subjective visual vertical and horizontal. Method: The validation of the standing computerised rod and frame test in the standing posture was obtained by comparing results (n = 74) between the sitting and standing positions with the Spearman's correlation coefficient. In addition, agreement between the two methods was analysed with the Bland-Altman method. Participants (n = 56) resisted with their neck muscles approximately 35% maximum isometric voluntary contraction force for 15 minutes on a purpose built apparatus in eight different directions. Wilcoxon signed rank tests analysed changes in horizontal and vertical rod and frame test between the neutral and all different directions of contraction. The changes of recorded unsigned vertical and horizontal errors for the combined frame condition in all situations of isometric contraction were analysed with two respective one-way repeated measures analysis of variance (ANOVA). Discussion: The Spearman's rho and Bland-Altman plots show that the Rod and Frame Test works equally well in sitting and standing positions. After muscle contraction, there were significant increases in error in all participants for both horizontal and vertical rod and frame tests, except after flexion. These errors were predominantly present after fatigue of muscles in the coronal plane of contraction. Proprioception alone cannot explain the difference in the rod and frame results between different muscle groups. It is suggested that an evolutionary advantage of developing improved subjective verticality awareness in the same direction as the main visual field could explain these findings. © 2014 Gosselin and Fagan

Duchenne muscular dystrophy: overview and future challenges Dystrofia = mięśniowa Duchenne’a: przegląd literatury i wyzwania w przyszłości

Duchenne muscular dystrophy is a muscle disease caused by mutation in the gene that encodes the cytoskeletal protein dystrophin. It is inherited in an X-linked recessive fashion. A number of therapies are continuously being developed to slow down the progression of the disease and increase patients’ life expectancy. Steroid use in Duchenne muscular dystrophy is associated with a lower mortality rate (hazard ratio = 0.24; 95% CI = 0.07–0.91; p = 0.0351). Although recent studies have concluded that prolonged steroid use is associated with short stature and overweight, a meta-analysis of 12 studies has shown that steroids can increase strength, muscle function, and quality of life. Restoration of dystrophin gene expression is the basis of genetically engineered therapies. Potential therapies of this type include exon skipping, the use of recombinant adeno- associated virus which delivers mini-dystrophin, and surrogate gene transfer. In their development, the common challenges are associated with the size of gene product and the origin of dystrophin gene expression. Stem cells are promising for future therapy. Regardless of the challenges and controversies associated with stem cells, several clinical trials show an increase of muscle strength in patients who have received such therapies

Efficacy of Depth Jump Parameters as a Recovery Monitoring Tool

Background: Fatigue monitoring is an important aspect for athletic coaches to monitor the level of readiness of an athlete. Monitoring of an athlete’s fatigue status helps identify the need to adjust one’s training program, identify injury risk, and help attain an athlete’s peak performance when it is most advantageous for them. More research is warranted that examines the effects of a comprehensive set of jump parameters to track recovery from muscle impairing exercise. This study focused on the onset of muscle soreness through eccentric resistance exercise. Purpose: The purpose of this project was to examine the efficacy of force plate GRF-derived data from depth jump (DJ), and peak force (PF) by maximum voluntary isometric contraction tests as a means to track neuromuscular recovery following a bout of eccentric exercise. A secondary aim was to evaluate soreness markers during the recovery phase. Methods: Thirty college aged, recreationally active students participated in this study. This study was a repeated measures design where each subject participated in 5 visits including a familiarization visit, an experimental visit (when the eccentric exercise was performed), and three follow up visits. The second visit included subjects performing the eccentric exercise intervention where they performed a 3 minute workout at 50% intensity. Testing including maximal voluntary isometric contractions MVICs and was done at pre- and post-exercise as well as 24, 48, and 96 h following the exercise session. Testing involved MVICs on the dynamometer (to determine peak force; PF), followed by DJ tests. Also, each subject was asked to complete a visual analog scale (VAS) to determine soreness upon arrival of each visit. All post intervention visits were identical in format except they did not do the exercise intervention. Results: There were no changes in DJ GRF variables nor PF, but there was a significant difference in soreness across the visits, suggesting that the eccentric exercise intervention on the Eccentron succeeded in inducing muscle damage. Conclusion: Data from this study suggest that despite participants experiencing significant soreness in the period that followed the eccentric protocol, there were no changes in ground reaction force parameters from a DJ performance nor in PF variables. Greater impairments to force generating capacities than what were found herein are required from an eccentric exercise intervention to determine whether DJ measures can adequately monitor fatigue characteristics

Клинический случай поражения периферической нервной системы в виде нейропатии локтевого нерва у больного с рассеянным склерозом

На основі власного досвіду описано кліничний випадок ураження периферичної нервової системи у вигляді нейропатії ліктьового нерву у хворого з вторинно-прогресуючим розсіяним склерозом. Надано огляд літератури за проблемою нетипового щодо розсіяного склерозу ураження структур периферичної нервової системи.The own data of the сlinical case of ulnar nerve neuropathy in the patient with secondary progressive multiple sclerosis is described. Literature data of atypical for multiple sclerosis pathology of the peripheral nervous system are analyzed

Estimation of Stature from Arm Span in Medical Students of Maharashtra, India

Background: Stature can be estimated from body parameters in dead and mutilated bodies using regression equation or multiplication factor. However, regression equations and multiplication factors are specific for the region only and canft be used in all population.  Aim: To formulate regression equation and multiplication factor for the estimation of stature from arm span (AS) for a region in Maharashtra, India. Subjects and Methods: It was a cross.sectional study, did over a period of 2 years, from October 2011 to September 2013. Four hundred students of three Government medical colleges of Maharashtra, aged 18.24 years were enrolled in the study. Stature and AS were measured and subjected to statistical analysis. Unpaired t.test and simple linear regression were used. Results: Stature and AS of 400 medical students (219 males and 181 females) were measured. Subjects were divided into six groups depending upon age. Simple regression equation and multiplication factor for male and female and for each age group were derived for estimation of stature. We found correlation coefficient (R) of 0.89 in male and 0.90 in female using simple regression, which shows strong correlation between stature and AS.Conclusion: Mean stature and AS of male were more than female with statistical significance. Stature can be accurately estimated from AS using simple regression equation or multiplication factor.Keywords: Arm span, Simple regression, Statur