Background and Aim: Cross-legged sitting is a common daily postural habit, yet its biomechanical effects on the lumbopelvic region and lower extremities remain insufficiently understood. This review aimed to synthesize evidence on the effects of sitting with crossed legs on rotational mobility and range of motion of the lumbar spine, pelvis, and hip joint.
Methods: A systematic search was performed in Google Scholar, PubMed, ScienceDirect, PEDro, and MedLib using the English keywords Leg Crossed, Hip and thigh range of motion, and Hip rotation. Persian databases including Magiran, Irandoc, IranMedex, MedLib, and SID were searched using the keywords legs crossed, range of motion of the pelvis, thigh and lumbar spine. The search covered studies published between September 2000 and September 2024. Studies of any design examining sitting posture effects on hip, pelvic, or lumbar ROM were eligible.
Findings: Ten studies met the inclusion criteria. Most reported that cross-legged sitting induces postural asymmetries, particularly increased external hip rotation and compensatory lumbar changes. Methodological heterogeneity due to variations in measurement tools, sample sizes, and participant ages led to inconsistent outcomes. Only a few studies explored links to low back pain, with inconclusive results.
Conclusion: Current evidence confirms a relationship between cross-legged sitting and altered hip-pelvis-spine kinematics. The proposed mechanism involves adaptive shortening of the hamstring and tensor fascia latae muscles, restricting thigh and back ROM. Although some evidence suggests a potential link to back pain, the scarcity of high-quality studies highlights the need for future prospective research with standardized methods.