LOWER CROSSED SYNDROME

Lower-Crossed Syndrome (LCS) - . In LCS, tightness of the thoracolumbar extensors on the dorsal side crosses with tightness of the iliopsoas and rectus femoris. Weakness of the deep abdominal muscles ventrally crosses with weakness of the gluteus maximus and medius. This pattern of imbalance creates joint dysfunction, particularly at the L4-L5 and L5-S1 segments, SI joint, and hip joint. Specific postural changes seen in LCS include anterior pelvic tilt, increased lumbar lordosis, lateral lumbar shift, lateral leg rotation, and knee hyperextension. If the lordosis is deep and short, then imbalance is predominantly in the pelvic muscles; if the lordosis is shallow and extends into the thoracic area, then imbalance predominates in the trunk muscles.

Causes

• Prolonged sitting, particularly with bad posture
• Physical inactivity
• Regular performance of sports and activities that involve an uneven stimulation of the muscles that are involved in LCS
• Poor exercise technique.
• Imbalanced strength training
• Genetic predispositions

 The development of LCS initiates a vicious cycle. Because the gluteals and abdominals are weak, their function is compromised, and other muscles such as the hamstrings and lower back muscles are recruited to assist them in performing activities such as walking, running, and squatting. This leads to overuse and tightness of the hamstrings and lower back muscles, and a further weakening of the abdominals and gluteals.