1 Department of Orthopaedic Surgery, South Miyagi Medical Center, Ogawara, Miyagi, Japan
2 Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Miyagi, Japan
3 Department of Orthopaedic Surgery, Iwate Prefectural Central Hospital, Morioka, Iwate, Japan
4 Department of Orthopaedic Surgery, JR Sendai Hospital, Sendai, Miyagi, Japan
5 Department of Orthopaedic Surgery, Matsuda Hospital, Sendai, Miyagi, Japan
Although the shoulder range of motion significantly decreases with advancing age, how the natural aging process affects the joint capsule, including the Coracohumeral Ligament (CHL), in healthy subjects is still unknown.
To use shear wave elastography to investigate the correlations between age, sex, and shoulder dominance, and elasticity of the CHL in healthy individuals.
Eighty-four healthy volunteers (mean age: 42.6; 39 men) were included in this study. They were divided into five groups based on age: 20s (20–29, n = 19), 30s (30–39, n = 17), 40s (40–49, n = 20), 50s (50–59, n = 13), and 60s (60–69, n = 15) groups. The elasticity of the CHL in the bilateral shoulders was evaluated at the neutral and 30° external rotation (ER at 30°) positions with the arm at the side while laying supine.
The elastic modulus was significantly greater in ER at 30° than in the neutral position regardless of sex or shoulder dominance (P < 0.001). Significant positive correlations between age and elasticity of the CHL were observed in both the neutral and ER at 30° positions regardless of shoulder dominance. Elasticity of the CHL was significantly greater with increasing age in both the neutral and ER at 30° positions on the dominant (P = 0.0022, P < 0.001, respectively) and non-dominant sides (P = 0.0199, 0.0014).
The elasticity of the CHL increased with age, and the ER at 30° position could demonstrate faint changes in CHL elasticity.
Level of Evidence:
Level 3 Case-control study.
Keywords: Shoulder dominance, Range of motion, Coracohumeral ligament, Shear wave elastography, Ligament elasticity, Frozen shoulder.
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