Joint mobility and joint stability are two parts of a patient’s musculoskeletal condition that physical therapists assess.
- Joint mobility is the amount of movement that occurs within a single joint. So this is not just how high you can raise your arm or how far you can bend your knee, but it is how much or how little “wiggle” there is within a joint. Us therapist call this “wiggle” joint play and rate joint mobility as mild, moderate or severe hypermobility (excessive movement) and mild, moderate, or severe hypomobility (limitation of movement, stiffness).
- Joint stability is made up of both static and dynamic stability. Static stability is made up of how well the structures in and around the joint support and keep the joint intact. The shape of the joint, the joint capsule, the ligaments and the joint cartilage play a role in the static stability of the joint. Dynamic stability is made up of one’s muscle control of the joint as you move.
So how does having too little joint mobility (hypomobility) affect someone?
Limitations in joint mobility will often be seen alongside limitations in range of motion. For example, someone with hypomobility of their spine may not be able to rotate as far to the left or right or may not be able to bend through a normal range forwards or backwards. An example of a severely hypomobile joint would be one that is fused (either surgically or due to pathology) and in this case no movement can or will occur at this joint. Frozen shoulders, people who have body part immobilized in a cast or brace for a period of time and post surgical scar tissue or decreased mobility are examples of common cases in which joint hypomobility is experienced. If a therapist assesses decreased joint mobility, then they can prescribe the appropriate joint mobilizations and stretches in order to address this issue and help the patient regain functional range of motion in order for them to perform their desired activity. Additionally, once increased movement is gained, then joint stability is also addressed. It is important for the therapist to help the patient develop the muscle control and joint stability through this newly gained range of motion in order to help prevent joint, muscle, or tendon irritation.
So how does having too much joint mobility affect someone?
People with too much joint mobility will be more prone to dislocations, subluxations, ankle sprains, sacroiliac joint dysfunction, muscle pains, and general fatigue. Gymnasts, dancers, acrobats, people who can pop their joints in and out of place, and those with Ehlers Danlos syndrome are typical examples of people who tend to demonstrate joint hypermobility. When there is too much joint mobility, that means the muscles have to work extra hard and be extra strong, and coordinated to provide dynamic stability in order to make up for the limited structural stability. Limited structural stability can be the result of ligament tears, congenital joint abnormalities, or connective tissue laxity. If joint hypermobility is found, a therapist will help prescribe a treatment program primarily based around relieving muscle restrictions resulting from overuse and building balanced muscle strength, endurance, balance, and control in order to focus on increasing dynamic stability to help prevent future subluxations, dislocation, joint sprains, and general wear-and-tear of the affected joint(s).
If you feel like you are experiencing issues with either increased or decreased joint mobility or decreased joint stability, don’t hesitate to contact a physical therapist especially if it is contributing to pain or limited ability to move or use your body normally. Physical therapy can help address these issues and help you return to your normal function.
