RESUMEN
OBJECTIVE: The purpose of this study was to assess levels of electromyographic activity measured from rectus capitis posterior major (RCPM) muscles of asymptomatic subjects as their heads moved from a self-defined neutral position to a retracted position. METHODS: A 2 × 2 within-subjects factorial research design was used. Disposable, intramuscular electrodes were used to collect electromyographic data from asymptomatic subjects between the ages of 20 and 40 years old. Data analysis was performed using mixed effects ß regression models. RESULTS: Activation of RCPM muscles was found to significantly increase (P < .0001) as the head moved from a self-defined neutral position to a retracted position. Rectus capitis posterior major muscle activation levels, measured as a function of head position, have not been previously reported. CONCLUSIONS: The findings from this study showed that RCPM muscle activation significantly increases during voluntary retraction of the head.
Asunto(s)
Electromiografía , Movimientos de la Cabeza/fisiología , Músculos del Cuello/fisiología , Adulto , Femenino , Humanos , MasculinoRESUMEN
There are many articles that support stretching, strengthening, good nutrition, hydration, rest, and ergonomics along with many other concepts that may be helpful in preventing repetitive stress injuries. The most conclusive literature proposes early recognition of onset symptoms, and immediate reduction or cessation of the casual activity. This is not well accepted by the musician, because this means an interruption of practice and performance. Just like any worker or athlete at risk for RSI, however, the musician must learn to recognise early signs and take the steps to limit damage to muscular and neural tissues. More studies are needed to provide evidence for effective treatment and prevention of RSI.
Asunto(s)
Trastornos de Traumas Acumulados/prevención & control , Ejercicios de Estiramiento Muscular , Música , Enfermedades Profesionales/prevención & control , Trastornos de Traumas Acumulados/fisiopatología , Humanos , Estilo de Vida , Fuerza Muscular , Enfermedades Profesionales/fisiopatología , Postura , Rango del Movimiento Articular , Articulación del Hombro/fisiopatologíaRESUMEN
OBJECTIVE: To examine the effects of occupational keyboard typing on median nerve shape and T2 relaxation and on forearm muscle T2 in professional typists with and without symptoms of carpal tunnel syndrome. DESIGN: Based on the Levine Carpal Tunnel Syndrome Symptom Severity scale (LCTSS), 12 female professional typist volunteers were divided into asymptomatic (LCTSS < 1.3, n = 5) and symptomatic (LCTSS > 1.3, n = 7) groups. Magnetic resonance images were acquired from wrist and forearms of all subjects before, immediately after, and 8 hrs after 3 hrs of typing. Forearm muscle T2 and median nerve T2 cross-sectional area and long/short axis ratio were evaluated by blinded observers. RESULTS: There was no difference between groups in any measured variable before typing. Median nerve T2 increased and long/short axis ratio decreased in asymptomatic subjects after typing, but there were no significant changes in symptomatic subjects. T2 increased in finger flexor muscles after typing, but there was no difference in the pattern of muscle T2 changes between groups. CONCLUSION: In magnetic resonance images of the median nerve at the carpal tunnel, swelling and T2 increases from baseline are a normal response to typing and may be less likely to occur in subjects with symptoms of carpal tunnel syndrome.