This cross-sectional study will include postmenopausal women under the age of 60 who visited the Physical Medicine and Rehabilitation outpatient clinic at Beylikdüzü State Hospital between June 25 and July 25, 2025. Participants must have undergone a bone mineral density (BMD) assessment within the past six months using Dual X-ray Absorptiometry (DXA). Both osteoporotic and non-osteoporotic patients will be enrolled. Sociodemographic data such as age, height, weight, and BMI will be recorded. Femoral neck and L1-L4 T-scores and BMD values will be obtained from existing DXA results. Information on osteoporosis treatment, presence of fecal incontinence, constipation, and medication use will be collected. In the second phase, sarcopenia will be assessed according to EWGSOP2 criteria using bioelectrical impedance analysis for skeletal muscle mass, handgrip strength, and the five-time sit-to-stand test. Differences between the osteoporotic and non-osteoporotic groups will be analyzed.

Inclusion Criteria:

• Women under 60 years of age who are postmenopausal.
• Patients with or without a diagnosis of osteoporosis:

Osteoporosis group: T-score ≤ -2.5 in femoral neck or L1-L4 region. Control group: T-score ≥ -1.0 in femoral neck and L1-L4 region.

-Patients who provide written informed consent to participate in the study.

Exclusion Criteria:

• Refusal to participate in the study.
• Presence of neuromuscular diseases that could cause muscle loss.
• History of infection, recent surgery, or trauma.
• Presence of psychiatric disorders.
• Cognitive impairment that could interfere with test performance or data reliability.
• Use of medications that could affect study outcomes (e.g., corticosteroids, muscle relaxants, or medications influencing bone/muscle metabolism).

Postmenopausal women under 60 years