Hip Abductor Strength Asymmetry: Relationship to Upper Extremity Injury in Professional Baseball Players

Abstract

Background: Hip strength is an important factor for control of the lumbo-pelvic-hip complex. Deficits in hip strength may affect throwing performance and contribute to upper extremity injuries. Hypothesis: Deficits in hip abduction isometric strength would be greater in those who sustained an upper extremity injury and hip strength would predict injury incidence. Study Design: Prospective cohort study. Level of Evidence: Level 3. Methods: Minor League baseball players (n = 188, age = 21.5 ± 2.2 years; n = 98 pitchers; n = 90 position players) volunteered. Hip abduction isometric strength was assessed bilaterally with a handheld dynamometer in side-lying position, expressed as torque using leg length (N·m). Hip abduction strength asymmetry was represented by [(trail leg/lead leg) × 100]. Overuse or nontraumatic throwing arm injuries were prospectively tracked. Poisson regression models were used to estimate relative risk ratios associated with hip asymmetry; confounders, including history of prior overuse injury in the past year, were included. Results: Hip abduction asymmetry ranged from 0.05% to 57.5%. During the first 2 months of the season, 18 players (n = 12 pitchers) sustained an upper extremity injury. In pitchers, for every 5% increase in hip abduction asymmetry, there was a 1.24 increased risk of sustaining a shoulder or elbow injury. No relationship between hip abduction strength and injury was observed for position players. Conclusion: Hip abduction asymmetry in pitchers was related to subsequent upper extremity injuries. The observed risk ratio indicates that hip abduction asymmetry may contribute a significant but small increased risk of injury. Clinical Relevance: Hip abduction muscle deficits may affect pitching mechanics and increase arm stress. Addressing hip asymmetry deficits that exceed 5% may be beneficial in reducing upper extremity injury rates in pitchers.

Identifying the Differences in Symmetry of the Anthropometric Parameters of the Upper Limbs in Relation to Manual Laterality between Athletes Who Practice Sports with and without a Ball

“…A series of studies highlighted the relationship between the asymmetric development of the muscle mass of the upper limbs and the dimensions of the bones in subjects who practice sports that involve predominantly unilateral technical executions [82][83][84]. Studies have shown that asymmetries between the upper and lower segments increase the risk of injury with an impact on health and sports performance [85,86].…”

Evolution of Hip Muscles Strength in Femoroacetabular Impingement Patients Treated by Arthroscopy or Surgical Hip Dislocation: A Retrospective Exploratory Study

“…Postoperative strength asymmetries can generate a risk of functional imbalance and might have important consequences. They have already been reported as a risk factor for musculoskeletal injuries [ 43 ] or for intrinsic hip pathologies such as osteoarthropathy [ 44 ] while possibly affecting structures beyond the concerned joint [ 45 ]. Setting up adequate strengthening exercises in order to rectify this strength asymmetry is, therefore, essential for patients both in the short- and long-term.…”