A study found that postmenopausal women with osteosarcopenia show reduced muscle-tendon stiffness and impaired dynamic balance compared to those with osteoporosis or healthy bone density.

Researchers conducted a comparative study on muscle-tendon stiffness and balance impairment in postmenopausal women with osteosarcopenia (OS), osteoporosis (OP), and normal bone mineral density. Their findings emphasize the biomechanical and functional deficits associated with OS.

Published in Aging Clinical and Experimental Research, the study enrolled 73 women aged 60 years or older. After screening with dual-energy X-ray absorptiometry (HOLOGIC DXA) T-scores and appendicular skeletal muscle mass index (ASMI), and excluding those with conditions such as secondary osteoporosis, musculoskeletal disorders, neurological conditions, and diabetes, 52 participants remained. These were categorized into OS (n=21; T-score ≤−2.5, ASMI <5.5 kg/m²), OP (n=21; T-score ≤−2.5, ASMI ≥5.5 kg/m²), and healthy groups (n=10; T-score >−1, ASMI ≥5.5 kg/m²). The OS group was significantly older (73.9±7.1 years) compared to both OP (64.3±4.4 years) and healthy (65.3±3.8 years) groups.

Using shear wave elastography (Mindray DC80), researchers measured muscle-tendon stiffness of the gastrocnemius medialis (GM) and Achilles tendon during rest and activation. Balance impairments were assessed via center-of-pressure (CoP) displacement in a curve-tracking task.

The OS group demonstrated significantly lower GM stiffness at rest compared to the OP and healthy groups (P < 0.001). During activation, GM stiffness remained significantly lower in the OS group compared to both other groups (P < 0.001). Similarly, Achilles tendon stiffness was significantly lower in the OS group both at rest and during activation compared to the OP and healthy groups (P < 0.001).

In the medial-lateral (ML) direction, the OS group exhibited significantly lower values for mean absolute error, standard deviation of absolute error, root mean square (RMS) error, and area compared to the OP group (P = 0.033, 0.011, 0.022, and 0.047, respectively). These reductions were also significant when comparing the OS group to the healthy group (P = 0.009, 0.008, 0.006, and 0.012, respectively). In the anterior-posterior direction, only the standard deviation of absolute error showed significant differences. Positive correlations were observed between ML CoP parameters and both GM and Achilles tendon stiffness during activation (r = 0.3-0.4, P < 0.05).

The OS group also demonstrated significantly higher Fall Efficacy Scale scores, indicating greater fear of falling compared to the other groups. The study identified significant reductions in muscle-tendon stiffness and balance control in OS. The researchers noted the importance of targeted functional rehabilitation exercises focused on ankle and hip strategies for postmenopausal women with OS.

Full disclosures can be found in the published study.