Skeletal problems associated with weak muscles in SMA include tight joints with limited range of movement, hip dislocations, spinal deformity, osteopenia, an increase risk of fractures and pain.  Weak muscles that normally stabilize joints such as the vertebral column lead to development of kyphosis and/or scoliosis and joint contracture.  Spine fusion is sometimes performed in people with SMA I/II once they reach the age of 8-10 to relieve the pressure of a deformed spine on the lungs. Furthermore, immobile individuals, posture and position on mobility devices as well as range of motion exercises, and bone strengthening can be important to prevent complications.  People with SMA might also benefit greatly from various forms of physiotherapy , occupational therapy and physical therapy.