Muscle balance can be defined as the equal length and strength of agonist and antagonist muscles that is necessary for normal movement and functionality of the body. The cause of muscle imbalance is the constant stress that muscles experience caused by poor posture and staying in incorrect positions during prolonged sitting, standing, or during repetitive bending and lifting movements that can increase spinal flexion and increase stress on the vertebrae, discs, and ligaments of the spine.
The soft tissue is enough to allow minimal intervertebral movements, and yet strong enough to prevent excessive movements and prevent nucleus injury. The function of the cover plate plays a very important role where it biomechanically suffers great compressive forces during everyday life and has adequate strength and elasticity to stabilize the spinal segment, but is also responsible for the diffusion of nutrients from the avascular intervertebral disc.
About 30% of people with AIS have reduced bone density, osteopenia, this reduced density is not only in the spine but in all bones of the body. This decreased density is directly related to the progression of scoliosis not only in people with AIS but also other types of scoliosis (adult).
Spinal deformities in adults can have a significant impact on their quality of life. Most often it occurs as a consequence of untreated or inadequately treated adolescent idiopathic scoliosis. Patients with adult scoliosis have a different clinical and radiological picture compared to patients with adolescent idiopathic scoliosis. Differences include degenerative changes within the curve, a natural history of deformity progression, and clinical symptoms.