Lower Crossed Syndrome (LCS), also known as distal or pelvic crossed syndrome, is a "S" shaped posture of the lower back that is characterized by tight hip flexors and lower back muscles associated with weak abdominal and gluteus maximus muscles. Tightness in the rectus femoris and iliopsoas crosses with tightness in the dorsal side thoraco-lumbar extensors in LCS. The gluteus maximus and medius are weak, and their weakness ventrally crosses over into the weakness of the deep abdominal muscles. Particularly in the L4-L5 and L5-S1 segments, SI joint, and hip joint, this pattern of imbalance results in joint dysfunction.(Das et al., 2017).

People who lead sedentary lives, such as office workers and sports, are more likely to acquire the illness because it is caused by repetitive or persistently bad postural habits, such as extended sitting, poor ergonomics, or activities involving constant lumbar flexion.

Due to compensatory patterns in movement brought on by muscle imbalances linked to LCS, lumbar curvature increases as muscular strength, flexibility, and mobility decrease. This causes people to frequently have severe postural instability, decreased range of Low back pain is a universal problem and lower crossed syndrome is one of the threatening combinations of biomechanical muscle imbalance due to excessive stress it places on the structures of lower back. People with such postural imbalance frequently complain of lower back pain and if it is left unchecked, this postural imbalance can generate a chronic pain condition of lower back that becomes more difficult to correct in later stages (Das et al., 2017).