ABSTRACT
BACKGROUND: Throwing athletes present alterations in shoulder rotation range of motion (ROM), but not much is known about the relationship between these alterations and performance measurements in volleyball practitioners. PURPOSE: To compare the passive ranges of motion of internal rotation (IR), external rotation (ER), and total rotation motion (TRM) of the shoulder in dominant and nondominant limbs of young volleyball athletes and to investigate their relationship with ball speed during serves with and without precision (inside and outside court, respectively). The possible association of anthropometrics and competitive practice time with these velocities was also investigated. STUDY DESIGN: Cross-sectional study. METHODS: Fifty-seven male volleyball athletes (mean age 17.11 ± 1.88 y; weight 74.68 ± 9.7 kg; height 1.87 ± 0.09 cm) were evaluated for shoulder IR and ER with a bubble goniometer and serve speed inside and outside court was measured with a radar gun. Simple and multiple regression analyses were applied to investigate associations of ROM, anthropometrics, and competitive practice time with serve speed. RESULTS: Dominant shoulders had diminished IR ROM compared to nondominant shoulders (59.1º ± 16.7º vs 66.4º ± 16.9º; p < 0.001) as well as diminished TRM (173.5º ± 31.8º vs 179.1º ± 29.9º; p < 0.001). Simple regression showed negative association between dominant ER and serve speed outside the court (p = 0.004). Positive associations existed between age and serve speed in both conditions (p < 0.001), BMI and speed inside (p = 0.009) and outside the court (p = 0.008), and between competitive practice time and speed inside (p = 0.008) and outside court (p = 0.003). However, multiple analysis confirmed only age (p < 0.001) and BMI to be associated with ball velocities (inside court p = 0.034; outside court p = 0.031). CONCLUSION: The results of this study demonstrated that young volleyball athletes presented lower IR and TRM of the shoulder in the dominant upper limb. Age and BMI were directly associated with ball velocities when serving. Passive rotation ROM did not have a relationship with this performance measurement. LEVEL OF EVIDENCE: 3b.
ABSTRACT
BACKGROUND: Weakness of the rotator cuff muscles can lead to imbalances in the strength of shoulder external and internal rotators, change the biomechanics of the glenohumeral joint and predispose an athlete to injury. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has demonstrated promising results in a variety of health conditions. However few studies addressed its potential approach in the realm of athletics. HYPOTHESIS/PURPOSE: The purpose of this study was to investigate if transcranial direct current stimulation (tDCS) technique increases the isometric muscle strength of shoulder external and internal rotators in handball athletes. STUDY DESIGN: Randomized, double-blind, placebo-controlled, crossover study. METHODS: Eight female handball players aged between 17 and 21 years (Mean=19.65; SD=2.55) with 7.1 ± 4.8 years of experience in training, participating in regional and national competitions were recruited. Maximal voluntary isometric contraction (MVIC) of shoulder external and internal rotator muscles was evaluated during and after 30 and 60 minutes post one session of anodal and sham current (2mA; 0.057mA/cm2) with a one-week interval between stimulations. RESULTS: Compared to baseline, MVIC of shoulder external and internal rotators significantly increased after real but not sham tDCS. Between-group differences were observed for external and internal rotator muscles. Maximal voluntary isometric contraction of external rotation increased significantly during tDCS, and 30 and 60 minutes post-tDCS for real tDCS compared to that for sham tDCS. For internal rotation MVIC increased significantly during and 60 minutes post-tDCS. CONCLUSIONS: The results indicate that transcranial direct current stimulation temporarily increases maximal isometric contractions of the internal and external rotators of the shoulder in handball players. LEVEL OF EVIDENCE: 2.
ABSTRACT
INTRODUÇÃO: No movimento de ataque, o equilíbrio do ritmo escapulotorácico exerce papel fundamental na eficiência do gesto esportivo, sendo a discinesia escapular comumente associadas a lesões específicas do ombro do arremessador. Dentre suas causas é frequentemente relatada a fadiga muscular consequente ao uso excessivo da musculatura periescapular. OBJETIVO: Avaliar a influência do treinamento na presença de discinesia escapular em atletas de voleibol. MÉTODOS: Trata-se de um estudo de coorte prospectivo, no qual foram avaliadas 12 atletas do gênero feminino praticantes de voleibol, que não possuíam cirurgias prévias nos ombros e praticavam no mínimo 10 horas de treinos semanais. Foi realizada avaliação pré e pós treino, no qual realizavam 30 min de aquecimento e 120 min de treino específico da modalidade. A discinesia escapular foi avaliada em 'SIM' ou 'NÃO', definida de acordo com a presença ou ausência de alterações no padrão de movimento escapulotorácico, respectivamente. RESULTADOS: A prevalência de discinesia nesta população foi identificada em nove das doze atletas na avaliação pré-treino (75%) e após a realização do treinamento uma atleta que não apresentava inicialmente alteração evoluiu com o padrão de discinesia, resultando na prevalência acumulada de 10 atletas (83%) nesta população. CONCLUSÃO: Concluiu-se que uma única sessão de treinamento foi capaz de aumentar a prevalência de discinesia escapular em 8% (ou uma atleta) das atletas de voleibol. .
INTRODUCTION: In the throwing motion, the balance of scapulothoracic rhythm plays a key role in the efficiency of the Sporting gesture. Scapular diskinesis is commonly associated to specific injuries of the throwing shoulder. Among the causes of scapular dyskinesia, muscle fatigue is often reported due to overuse of the periescapular muscles. OBJECTIVE: To evaluate the influence of training in the presence of scapular dyskinesis in volleyball athletes. METHODS: This is a prospective cohort study in which twelve female athletes practicing volleyball, who had no previous surgeries on the shoulders and practicing at least 10 hours of weekly workouts were evaluated. Assessment pre and post workout was performed, which consisted of 30 min warm up and 120 min of specific training. Scapular dyskinesia was evaluated as 'YES or 'NO' as for the presence or absence of abnormalities in the scapular-thoracic movement, respectively. RESULTS: As a result of this study we identified a prevalence of scapular dyskinesis in nine athletes from twelve in the pre-training (75%) and after the training session only one athlete evolved with standard dyskinesia, resulting in the cumulative prevalence of 10 athletes (83%) in this population. CONCLUSION: This study concluded that a single training session was able to increase the prevalence of scapular dyskinesia in 8% (or one athlete) of volleyball players. .
INTRODUCCIÓN: En el movimiento de ataque, el equilibrio del ritmo escapulotorácico ejerce un papel fundamental en la eficiencia del gesto deportivo, siendo la disquinesia escapular comúnmente asociada a lesiones específicas del hombro del lanzador. Entre sus causas es frecuentemente relatada la fatiga muscular como consecuencia por el uso excesivo de la musculatura periescapular. OBJETIVOS: Evaluar la influencia del entrenamiento en la presencia de la disquinesia escapular en atletas de voleibol. MÉTODOS: Se trata de un estudio de cohorte prospectivo, en el que fueron evaluadas 12 atletas del género femenino practicantes de voleibol, que no poseían cirugías previas en los hombros y practicaban como mínimo 10 horas de entrenamientos semanales. Fueron realizadas evaluaciones, antes y después del entrenamiento, que tenían 30 minutos de calentamiento y 120 minutos de entrenamiento específico de la modalidad. La disquinesia escapular fue graduada en "SI" o "NO", definida de acuerdo con la presencia o ausencia de alteraciones en el estándar de movimiento escapulotorácico, respectivamente. RESULTADOS: La prevalencia en esta población fue identificada en nueve atletas en la evaluación antes del entrenamiento (75%) y después de la realización del entrenamiento una atleta que no presentaba alteración inicialmente evolucionó con el estándar de disquinesia, resultando en la prevalencia acumulada de 10 atletas (83%) en esta población. CONCLUSIÓN: Se concluye que una única sesión de entrenamiento fue capaz de aumentar la prevalencia de disquinesia escapular en 8% (o una atleta) de las atletas de voleibol. .
