Affiliations: [a] Groupe de Recherche sur le Handicap de l'Appareil
Locomoteur (G.R.H.A.L), Bois Guillaume, France | [b] Centre d'Etudes des Transformations des
Activités Physiques et Sportives (C.E.T.A.P.S, JE2318), Rouen,
France | [c] Institut Régional Médico-Sportif de
Haute Normandie (I.R.M.S.H.N), C.H.U. Bois Guillaume, France
Note: [] Address for correspondence: CETAPS, Faculté des Sciences
du Sport, Bvd Siegfried, 76821 Mont Saint Aignan Cedex, France. Tel.: +33 232
10 77 93; Fax: +33 232 10 77 93; E-mail: [email protected]
Abstract: Objective: To determine the strength ratios in the shoulder rotator
muscles of teenage baseball players, using a new test position. Methods: Ten asymptomatic baseball players of the French cadet team
(15.87 ± 0.80 yr) underwent dynamic isokinetic strength assessment of
the shoulder rotators at two angular velocities: 90 and
180°.s^{-1}. The peak torque of the internal rotators
(IR) and external rotators (ER) was recorded. One conventional ratio and two
dynamic ratios were determined at each angular velocity. The mean group values
were statistically analyzed. Results: Mean ER peak torque was significantly higher in the
dominant than in the non-dominant arm at both velocities (p < 0.05). The
dynamic ratio (ER conc/IR ecc) was significantly higher in the dominant than in
the non-dominant arm (p < 0.01). In the same position, baseball players had
higher conventional and dynamic ratios (IR conc/ER ecc) than those reported in
the literature for sedentary subjects. Conclusion: Intensive baseball practice affects the shoulder rotator
muscles. The IR values indicated greater strength than in sedentary subjects.
The difference in ER between the dominant and non-dominant arms underlines the
effect of pitching technique and suggests the need for further
investigations.
