In SMA, muscle weakness can cause several complications. These complications are referred to as orthopedic or musculoskeletal issues.
Common musculoskeletal issues include:
- Contractures, which limit the range of motion in a joint
- Bone fractures
- Hip dislocation
- Spinal deformities, such as scoliosis and kyphosis
- Scoliosis, an abnormal bending of the spine to the side—often "C-shaped"—that affects the balance of the trunk during sitting and/or standing. This spinal deformity can lead to obliquity of the base of the spine, pelvis, which can lead to an asymmetric and/or excessive pressure on hips and buttocks leading to skin breakdown. Scoliosis often results in twisting of the chest and rib cage that impair lung function by restricting motion of the chest and diaphragm during breathing.
- Kyphosis, an abnormal flexion and/or extension (lordosis) of the spine.
Spinal deformity is often a combination of scoliosis and kyphosis. Treatment can be through modification of the wheel chair seating system, use of braces and if severe, through surgical interventions that help straighten the spine and chest.
Musculoskeletal issues can cause pain, as well as difficulty sitting, standing, or performing normal daily activities.
Doctors and therapists classify individuals with SMA as either “non-sitters,” “sitters,” “standers,” or “walkers” (or “standers/walkers”), based on the highest physical milestone achieved.
This classification helps them create a proactive plan to:
- Identify which complications pose the greatest risk to the functional well-being of an individual.
- Choose the right preventative measures.
- Choose the best course of treatment if complications do occur. For example, a “sitter” with joint contractures will have a different course of treatment than a “stander” with contractures.
The Musculoskeletal Team
As with all medical issues in SMA, decisions on treatment of musculoskeletal problems should be made with an interdisciplinary healthcare team, who can evaluate all aspects of the situation.
Often, the musculoskeletal team for an individual with SMA will include:
- An occupational therapist (OT). OTs work primarily with the arms and hands. They focus on activities such as feeding, dressing, and other skills. They may recommend and make splints, and teach exercises to maintain range of motion and improve function. They may recommend equipment to help with some of these skills and activities.
- A physical therapist (PT). PTs work primarily with the legs and feet. They focus on mobility. They may recommend orthotics, and teach exercises to maintain range of motion and improve function. They may recommend equipment such as special seats, strollers, and wheelchairs.
- An orthotist. As the name might suggest, a orthotist focuses on making and adjusting orthotics
- A pediatric orthopedic surgeon. Orthopedic surgeons work with OTs, PTs and rehabilitation physicians. For conditions like hip instability or spinal deformity that don’t respond to non-surgical treatment, surgery may be an option. In this case, a surgeon will be brought in to evaluate and perform the surgery.
At-Home Musculoskeletal Care
Many times, the musculoskeletal team will prescribe activities that can be done at the therapist’s office, or with the child and parents at home—oftentimes both. This may include:
- Daily exercises to improve or maintain range of motion
- Use of equipment such as braces or a stander
- Supplemental calcium and vitamin D as part of the individual’s nutrition plan, if bone density is compromised
- Ambulatory Guidelines
- Cure SMA: Musculoskeletal System Care Series Booklet
- Early Treatment of Scoliosis in SMA Presentation
- Evaluation of Therapeutic Electrical Stimulation for SMA Types II and III
- Exercise in Motor Neuron Diseases Article
- Exercise and Oxidative Capacity in SMA-Madsen et al
- Frequently Asked OT Questions for SMA
- Frequently Asked PT Questions for SMA
- Giving Thanks Article
- Growing Rods Article
- North American Riding (Hippotherapy) website
- Power Mobility Evaluation Report
- Power Mobility: Key Elements for a Successful Letter of Medical Necessity
- Power Mobility and Power Wheelchairs for Children Bibliography and Resources
- Power Mobility Skills Checklist
- Resistive Exercise and SMA-Lewelt et al
- Scoliosis Research Society webpage
- Stand up for your stander letter
- The Hidden Twist: Scoliosis Article
- Therapeutic Electrical Stimulation and SMA- Fehlings et al