Incorporation of the Kinetic Chain Into Shoulder-Elevation Exercises: Does It Affect Scapular Muscle Activity?
J Athl Train
; 55(4): 343-349, 2020 Apr.
Article
en En
| MEDLINE
| ID: mdl-32160060
ABSTRACT
CONTEXT Scapular rehabilitation exercises should focus on selective activation of weaker muscles and minimal activation of hyperactive muscles. For rehabilitation of overhead athletes, single-plane open chain exercises below 90° of shoulder elevation are often recommended. Moreover, incorporating the kinetic chain in shoulder rehabilitation exercises is advised and has been suggested to influence scapular muscle activity levels. OBJECTIVE:
To study the influence of kinetic chain incorporation during 5 variations of a shoulder-elevation exercise on scapular muscle activity.DESIGN:
Cross-sectional study.SETTING:
University laboratory. PATIENTS OR OTHERPARTICIPANTS:
Thirty-one asymptomatic participants (15 men, 16 women). MAIN OUTCOME MEASURE(S) The electromyographic activity of the upper (UT), middle (MT), and lower (LT) trapezius, and serratus anterior was determined during 5 variations of bilateral elevation with external rotation (1) open-hand position (reference exercise), (2) closed-hand position, (3) dynamic bipedal squat, (4) static unipedal squat, and (5) dynamic unipedal squat on the contralateral leg. All data were normalized as a percentage of maximal voluntary isometric contraction (MVIC).RESULTS:
A closed-hand position (exercise 2) instead of an open-hand position (exercise 1) resulted in lower MT (mean difference = 3.44% MVIC) and LT (mean difference = 7.76% MVIC) activity. Incorporating the lower limb (exercises 3-5) increased UT activity when compared with exercise 1 (mean differences = 3.67, 2.68, 5.02% MVIC, respectively), which in general resulted in increased UTââMT ratios. Additionally, LT activity decreased when a dynamic unipedal squat was added (mean difference 4.90% MVIC). For the serratus anterior, the greatest activity occurred during elevation in a static unipedal squat position (exercise 4, 22.90% MVIC).CONCLUSIONS:
Incorporating the kinetic chain during shoulder-elevation exercises influenced scapular muscle activity and ratios. In particular, incorporating the lower limb resulted in more UT activity, whereas the open-hand position increased MT and LT activity.Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Traumatismos en Atletas
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Terapia por Ejercicio
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Músculos Superficiales de la Espalda
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Lesiones del Hombro
Tipo de estudio:
Diagnostic_studies
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Observational_studies
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Prevalence_studies
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Risk_factors_studies
Límite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
J Athl Train
Año:
2020
Tipo del documento:
Article
País de afiliación:
Bélgica