HYPOTHESIS: Objective documentation is needed of shoulder internal and external rotator strength using hand-held dynamometry in selected positions commonly used in a clinic. We compared strength measures and unilateral ratios between gender, limbs (dominant, nondominant), and 3 testing positions. We hypothesized that men would be stronger than women, the dominant shoulder would be stronger than the nondominant shoulder, and the seated neutral (0° adduction) and seated 30° abduction, 30° scaption, 30° diagonal (30°-30°-30°) positions would be stronger than the prone at 90°-90° position. MATERIALS AND METHODS: Three positions (prone at 90°, seated at neutral, and seated at 30°-30°-30°) were evaluated in 181 individuals using hand-held dynamometry. Three separate 3-factor (limb by position by gender) analyses of variance were conducted on internal rotation, external rotation, and unilateral ratios. RESULTS: Although the dominant limb was significantly stronger (P < .001) than the nondominant for internal rotation, there was no difference for external rotation. The external rotators demonstrated significantly greater strength in the prone at 90° position compared with the seated at neutral (P = .001) and seated at 30°-30°-30° (P = .002) positions. The internal rotators demonstrated significantly greater (P = .036) strength in the neutral position than in the prone at 90° position for the women. The unilateral ratio of external rotators/internal rotators ranged from 86% to 99%. For the women, the prone at 90° ratio was significantly greater than seated at neutral (P = .001) and seated at 30°-30°-30° (P = .001) positions. Moderate strength relationships (r = 0.506 to 0.572) were revealed between body mass and all strength measures. DISCUSSION: The results of this study provide evidence to interpret normative data, bilateral comparisons and unilateral ratios of the internal/external rotators in the 3 selected positions. CONCLUSION: Because there are no differences between the seated at neutral and 30°-30°-30° positions and the advantages it offers, we recommend the 30°-30°-30° position for testing and the initiation of rehabilitation.
HYPOTHESIS: Objective documentation is needed of shoulder internal and external rotator strength using hand-held dynamometry in selected positions commonly used in a clinic. We compared strength measures and unilateral ratios between gender, limbs (dominant, nondominant), and 3 testing positions. We hypothesized that men would be stronger than women, the dominant shoulder would be stronger than the nondominant shoulder, and the seated neutral (0° adduction) and seated 30° abduction, 30° scaption, 30° diagonal (30°-30°-30°) positions would be stronger than the prone at 90°-90° position. MATERIALS AND METHODS: Three positions (prone at 90°, seated at neutral, and seated at 30°-30°-30°) were evaluated in 181 individuals using hand-held dynamometry. Three separate 3-factor (limb by position by gender) analyses of variance were conducted on internal rotation, external rotation, and unilateral ratios. RESULTS: Although the dominant limb was significantly stronger (P < .001) than the nondominant for internal rotation, there was no difference for external rotation. The external rotators demonstrated significantly greater strength in the prone at 90° position compared with the seated at neutral (P = .001) and seated at 30°-30°-30° (P = .002) positions. The internal rotators demonstrated significantly greater (P = .036) strength in the neutral position than in the prone at 90° position for the women. The unilateral ratio of external rotators/internal rotators ranged from 86% to 99%. For the women, the prone at 90° ratio was significantly greater than seated at neutral (P = .001) and seated at 30°-30°-30° (P = .001) positions. Moderate strength relationships (r = 0.506 to 0.572) were revealed between body mass and all strength measures. DISCUSSION: The results of this study provide evidence to interpret normative data, bilateral comparisons and unilateral ratios of the internal/external rotators in the 3 selected positions. CONCLUSION: Because there are no differences between the seated at neutral and 30°-30°-30° positions and the advantages it offers, we recommend the 30°-30°-30° position for testing and the initiation of rehabilitation.
Authors: Ann M J Cools; Fran Vanderstukken; Frédéric Vereecken; Mattias Duprez; Karel Heyman; Nick Goethals; Fredrik Johansson Journal: Knee Surg Sports Traumatol Arthrosc Date: 2015-08-21 Impact factor: 4.342
Authors: Emma M Baillargeon; Daniel Ludvig; M Hongchul Sohn; Constantine P Nicolozakes; Amee L Seitz; Eric J Perreault Journal: J Electromyogr Kinesiol Date: 2019-05-23 Impact factor: 2.368