The impact of hypermobility spectrum disorders on musculoskeletal tissue stiffness: an exploration using strain...

Hypermobility spectrum disorders (HSDs) are conditions associated with chronic joint pain and laxity. HSD's diagnostic approach is highly subjective, its validity is not well studied, and it does not consider many of the most commonly affected joints. Strain elastography (SEL) reflects musculoskeletal elasticity with sonographic images. The study explored the impact of HSD on musculoskeletal elasticity using SEL. A cross-sectional design compared 21 participants with HSD against 22 controls. SEL was used to assess the elasticity of the deltoid, biceps brachii, brachioradialis, rectus femoris, and gastrocnemius muscles, and the patellar and Achilles tendon. SEL images were analyzed using strain index, strain ratio, and color pixels. Mean strain index (standard deviation) was significantly reduced in the HSD group compared to the control group in the brachioradialis muscle 0.43 (0.10) vs. 0.59 (0.24), patellar 0.30 (0.10) vs. 0.44 (0.11), and Achilles tendons 0.24 (0.06) vs. 0.49 (0.13). Brachioradialis muscle and patellar tendon's strain ratios were significantly lower in the HSD group compared to the control group, 6.02 (2.11) vs. 8.68 (2.67) and 5.18 (1.67) vs. 7.62 (1.88), respectively. The percentages (%) of red color (soft tissues) in the SEL images were significantly increased in the HSD group compared to the control group in the biceps brachii muscle, 34.72 (7.82) vs. 26.69 (3.89), and Achilles tendon, 18.14 (13.21) vs. 5.59 (8.23) (p ≤ 0.01). The elasticity of the musculoskeletal system seems to be lower in people with HSD. SEL could be a supplementary tool for diagnosing and monitoring HSD.