Upper crossed syndrome (UCS)

Upper crossed syndrome (UCS) refers to the imbalance of weakness and tightness in the neck, shoulder, chest, and back muscles commonly caused by poor posture. Some postural changes that can be seen are forward head posture, rounded shoulders, and winging of your shoulder blades. It should be taken into consideration that this posture alone may not be the only contributing factor to neck, shoulder or mid-back pain but just one of several potential issues that may need to be addressed.

When in a forward head and forward rounded shoulder position for a prolonged amount of time, the muscles in our chest (pectoralis) and upper back (upper trapezius and levator scapulae) are placed in a shortened position, while the muscles in our neck (deep neck flexors) and mid-low back (scapular retractors, lower trapezius and serratus anterior) become weak. These muscular imbalances can then lead to dysfunctional movement patterns and discomfort in the neck and shoulders, as well as back. This can make it difficult to do daily activities like working, driving, and sitting for long periods.

Physical therapists can perform evaluations to determine if this suboptimal positioning is contributing to a variety of conditions at the neck, mid-back or shoulders. Postural conditions such as these can be treated with physical therapy to help correct muscular imbalances by using a combination of activity modification and therapeutic exercises like stretching, strengthening and mobility to improve posture and overall comfort with movement.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7692548/