Measurement of Glenohumeral Internal Rotation in Asymptomatic Tennis Players and Swimmers
Authors: Renato Rangel Torres and João Luiz Ellera Gomes
References: Am J Sports Med May 2009 vol. 37 no. 5 1017-1023
Background Glenohumeral internal rotation deficit, often diagnosed in players of overhead sports, has been associated with the development of secondary shoulder lesions.
Hypothesis Asymptomatic players of different overhead sports will exhibit variable degrees of glenohumeral internal rotation deficit.
Study Design Cross-sectional study; Level of evidence, 3.
Methods Fifty-four asymptomatic male volunteers (108 shoulders) divided into 3 groups (tennis players, swimmers, control group) underwent measurements of glenohumeral internal and external rotation using clinical examination with scapular stabilization. Measurements of dominant and nondominant shoulders were compared within and between groups. Glenohumeral internal rotation deficit (GIRD) was defined as the difference in internal rotation between the nondominant and dominant shoulders.
Results In tennis players, mean GIRD was 23.9° ± 8.4° (P < .001); in swimmers, 12° ± 6.8° (P < .001); and in the control group, 4.9° ± 7.4° (P = .035). Dominant shoulders showed significant difference between all groups, and the difference in internal rotation of the dominant shoulder between the group of tennis players in comparison with the control group (27.6°, P < .001) was greater than the difference in internal rotation of the dominant shoulder found in the group of swimmers compared with the control group (17.9°, P < .001). Between tennis players and swimmers, the difference in internal rotation of the dominant shoulder was 9.7° (P = .002).
Conclusion Dominant limbs showed less glenohumeral internal rotation than the nondominant limbs in all groups, with the deficit in the group of tennis players about twice the deficit found for swimmers. Mean difference between limbs in the control group was less than 5°, which is within normal parameters according to most studies. There were statistically significant differences between all groups when dominant shoulders were compared with each other, differences that were not compensated by external rotation gain. Tennis players had the least range of motion, followed by swimmers.