RESUMEN
OBJECTIVES: To investigate if there is a difference in muscle activity for overhead athletes before and after an intervention with correction of both core and scapula compared to no intervention and is there a difference between overhead athletes with or without shoulder pain. DESIGN: Controlled laboratory EMG study including intervention. SETTING: University EMG laboratory. PARTICIPANTS: Sixty overhead athletes, 30 with shoulder pain and 30 healthy controls were included performing plyometric rotational shoulder exercise. MAIN OUTCOMES: Half of the participants received an intervention the other half were controls with no intervention. EMG muscle activity from 10 scapular, thoraco-humeral and trunk muscles were measured. RESULTS: There were no significant differences in muscle activation levels between the groups with or without intervention. For the shoulder pain group, there were significant lower activity in Upper Trapezius when repeating the exercise. The shoulder pain group had significant higher activity in Pectoralis Major compared to the Healthy Control group. CONCLUSIONS: Most differences were found between the pre- and post-test. Repetition of the exercise seems to be more important than verbal and tactile instructions. Comparing the shoulder pain group with the healthy controls confirms previous findings that, pain patients recruit muscles differently from healthy persons.
Asunto(s)
Ejercicio Pliométrico , Músculos Superficiales de la Espalda , Atletas , Electromiografía , Retroalimentación , Humanos , Músculo Esquelético , Escápula , Hombro , Dolor de HombroRESUMEN
ABSTRACT: Werin, MB, Maenhout, AG, Icket, J, Jacxsens, N, Kempkes, E, and Cools, AM. Does the activity in scapular muscles during plyometric exercises change when the kinetic chain is challenged?-An EMG study. J Strength Cond Res 36(7): 1793-1800, 2022-Plyometric exercises for the shoulder are used in rehabilitation and in workout regime when the sport demands high speed power training. The aim of this clinical laboratory electromyography (EMG) study was to determine whether scapular muscle performance differs during plyometric shoulder exercises when changing the demand on the kinetic chain. Thirty healthy overhead athletes, with a mean age of 22.7 years (±2.2), performed 6 exercises, with both a low and a high demand on the kinetic chain, in prone, side and standing in positions. The EMG activity of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) on the tested side and bilateral of gluteus maximus (GM) and abdominal oblique externus (OE) was registered with wireless surface EMG. Intermuscular muscle ratios UT/SA, UT/MT, and UT/LT were also calculated. The level of significance set for the study was alpha = 0.05. The muscle ratio UT/SA was significantly lower (p < 0.05) when high demand on the kinetic chain compared with low. SA muscle activity showed significantly (<0.001) higher values in the prone position with high demand on the kinetic chain compared with low. All 3 trapezius muscle parts had significantly higher values (p < 0.001) in the prone compared with side and standing positions. The GM and OE showed significantly higher (p ≤ 0.01) activity in positions more demanding for the kinetic chain. When composing a strengthening or a rehabilitation program for athletes, the knowledge of how scapular and trunk muscles interact can be used to amplify the strengthening effect.
Asunto(s)
Ejercicio Pliométrico , Músculos Superficiales de la Espalda , Adulto , Electromiografía , Humanos , Músculo Esquelético/fisiología , Escápula/fisiología , Hombro/fisiología , Músculos Superficiales de la Espalda/fisiología , Adulto JovenRESUMEN
OBJECTIVES: To investigate if there is a difference in muscle activity patterns during high load plyometric shoulder exercises between overhead athletes with and without shoulder pain. DESIGN: Controlled laboratory EMG study. SETTING: University EMG Laboratory. PARTICIPANTS: Sixty overhead athletes, 30 with shoulder pain and 30 healthy controls were included. MAIN OUTCOME MEASURES: The EMG activity of Upper Trapezius (UT), Middle Trapezius (MT), Lower Trapezius (LT), Serratus Anterior (SA), Latissimus Dorsi (LD) and Pectoralis Major (PM) on the tested side and bilateral on Abdominal Obliques Externus (OE) muscles was registered with wireless surface EMG during 3 rotational plyometric shoulder exercises in 3 positions, prone, sidelying and standing. RESULTS: A significant higher muscle activity was found in the shoulder pain group for MT together with an overall significant higher activity in the thoraco-humeral and abdominal muscles compared to healthy controls. CONCLUSIONS: When rehabilitating the overhead athlete with shoulder pain, shoulder muscles together with both thoraco-humeral and abdominal muscles need to be engaged.
Asunto(s)
Músculo Esquelético/fisiología , Ejercicio Pliométrico , Dolor de Hombro/fisiopatología , Adolescente , Adulto , Estudios de Casos y Controles , Electromiografía , Femenino , Humanos , Masculino , Extremidad Superior/fisiología , Adulto JovenRESUMEN
BACKGROUND: Plyometric shoulder exercises are commonly used to progress from slow analytical strength training to more demanding high speed power training in the return to play phase after shoulder injury. The aim of this study was first, to investigate scapular muscle activity in plyometric exercises to support exercise selection in practice and second, to enhance understanding of how scapular muscles are recruited during the back and forth movement phase of these exercises. METHODS: Thirty-two healthy subjects performed 10 plyometric exercises while surface EMG-activity of the scapular muscles (upper (UT), middle (MT) and lower trapezius (LT) and serratus anterior (SA)) was registered. A high speed camera tracked start and end of the back and forth movement. RESULTS: Mean scapular EMG activity during the 10 exercises ranged from 14.50% to 76.26%MVC for UT, from 15.19% to 96.55%MVC for MT, from 13.18% to 94.35%MVC for LT and from 13.50% to 98.50%MVC for SA. Anova for repeated measures showed significant differences in scapular muscle activity between exercises (p<0.001) and between the back and forth movement (p<0.001) within exercises. CONCLUSION: Plyometric shoulder exercises require moderate (31-60%MVC) to high (>60%MVC) scapular muscle activity. Highest MT/LT activity was present in prone plyometric external rotation and flexion. Highest SA activity was found in plyometric external rotation and flexion with Xco and plyometric push up on Bosu. Specific exercises can be selected that recruit minimal levels of UT activity (<15%): side lying plyometric external rotation and horizontal abduction or plyometric push up on the Bosu. The results of this study support exercise selection for clinical practice.