A joint contracture is a permanent or semi-permanent tightening of the soft tissues around a joint, including muscles, tendons, ligaments, and skin, that restricts the joint’s normal range of motion. The joint essentially gets “stuck,” unable to fully bend or straighten. Contractures can range from mild (retaining 60% to 90% of normal motion) to severe (less than 30% of normal motion) to complete ankylosis, where the joint has no movement at all.
What Happens Inside the Joint
Contractures develop through two main processes that reinforce each other: muscle atrophy and tissue fibrosis. When a joint stays in one position for too long, the muscle fibers physically shrink. Under a microscope, the cross-sectional area of muscle fibers decreases and the fibers themselves shorten. At the same time, the body ramps up protein breakdown in those unused muscles while slowing down the production of new muscle protein. The muscle is essentially being dismantled from the inside.
The second process is fibrosis, which is the buildup of collagen (the tough structural protein in connective tissue) in and around the muscle. Collagen accumulates in the layers of tissue that wrap around muscle fibers and muscle bundles. This excess collagen makes the tissue stiffer and less stretchy, directly reducing how far the joint can move. Early on, the limitation comes mainly from shortened muscle fibers. Over time, the collagen fibers rearrange into a tighter pattern, and the restriction becomes more structural and harder to reverse. A low-oxygen environment inside the immobilized muscle accelerates this scarring process.
Common Causes
The single most common cause of contractures is immobilization. Any situation that keeps a joint in one position for an extended period puts you at risk. That includes wearing a cast for several weeks, being hospitalized for a serious injury or surgery, or being confined to a bed or wheelchair due to illness.
Neurological conditions are another major driver. Stroke and cerebral palsy disrupt communication between the brain and muscles, which can leave muscles either paralyzed or locked in a state of constant over-contraction called hypertonia. In a study of people who had a severely disabling stroke, 60% developed at least one contracture within the first year.
Other causes include:
- Burns and wounds. Significant tissue loss from burns, infected wounds, or surgery creates contraction scars that pull the surrounding skin and soft tissue tight.
- Inherited conditions. Diseases that affect how connective tissue or muscle develops, such as congenital myopathies or spinal muscular atrophy, can cause contractures from childhood onward.
- Poor blood flow (ischemia). When tissues don’t get enough blood supply, chronic inflammation sets in, followed by scarring that stiffens the joint.
How Contractures Are Measured
Clinicians measure contractures using a goniometer, a simple protractor-like device placed along the joint to measure its range of motion in degrees. The key measurement is passive range of motion, meaning how far the joint moves when someone else moves it for you, removing any effect of muscle weakness. A contracture is recorded as the number of degrees the joint falls short of its full range. For example, a finger that should straighten to 0° but stops at 10° short would be recorded as a 10-degree flexion contracture.
The AMA classifies severity based on how much normal motion remains. Mild contractures retain 60% to 90% of normal range, moderate contractures retain 30% to 60%, and severe contractures fall below 30%. Complete loss of all motion is called ankylosis.
What Contractures Feel Like Day to Day
The experience depends on which joint is affected and how severe the restriction is. A mild contracture in a finger might feel like stiffness that won’t fully release. A severe contracture in a knee or hip can make walking impossible, force you into awkward postures, and cause pain both in the contracted joint and in other parts of the body that compensate for it.
Contractures create a cascade of secondary problems. Skin folds trapped in a permanently bent joint become warm, moist environments prone to breakdown and infection. People with hand contractures that curl the fingers into a fist often struggle with hygiene, and the trapped skin can develop painful sores. Falls are extremely common: in the stroke study mentioned earlier, 73% of participants experienced falls in the year following their stroke, with contractures contributing to impaired balance and gait. Pressure sores affected 22% of the same group. Depression, pain, and shoulder problems rounded out the most frequent complications.
Non-Surgical Treatment
The primary treatment for contractures is sustained stretching to gradually lengthen the shortened tissues. This can be done manually (a therapist or caregiver moving the joint through its range) or with devices like splints, orthoses, and serial casts that hold the joint in a lengthened position for hours at a time.
The amount of daily stretch varies widely depending on the joint and the severity of the contracture. A large review of stretching studies found that prescribed stretch times ranged from five minutes to 24 hours per day, with a median of about seven hours daily over a median treatment period of five weeks. In practice, many treatment plans involve wearing a splint or orthosis for 8 to 12 hours overnight, often combined with shorter stretching sessions during the day. Some protocols call for nearly round-the-clock splinting. For example, ankle-foot orthoses worn 20 to 22 hours per day between casting periods, or knee extension splints worn three hours a day, five days a week for six months.
Serial casting is another approach, particularly for neurological conditions like spinal muscular atrophy. A cast holds the joint at a slightly more extended position, and every few days or weeks, the cast is replaced with a new one that pushes the range a bit further. This technique gradually coaxes the tissues into a longer resting position. Consensus guidelines for serial casting in spinal muscular atrophy were recently developed through expert panels, though specific evidence guiding the exact parameters is still limited.
When Surgery Becomes Necessary
Surgery is typically reserved for contractures that haven’t responded to physical therapy, splinting, or other conservative treatments. The most common scenario involves contractures that cause a non-functional limb, significant pain, or skin infections that can’t be managed any other way.
One procedure is percutaneous tenotomy, a minimally invasive technique where a surgeon cuts through the shortened tendon using a small needle or blade inserted through the skin. This can be done under local anesthesia, which makes it an option for frail or elderly patients who can’t tolerate general anesthesia or open surgery. Depending on the severity, the surgeon may do a total tenotomy (completely cutting the tendon, which permanently stops that muscle from functioning) or a hemitenotomy (making partial cuts at different points to lengthen the tendon while preserving some function).
Open surgical release is a more involved option for severe contractures, involving direct incision to release the tight structures around the joint. Recovery from any contracture surgery typically requires an intensive rehabilitation program afterward to maintain the range of motion gained, since the same biological processes that caused the original contracture will try to reassert themselves.
Preventing Contractures
Prevention centers on movement and positioning, and it’s far more effective than trying to reverse an established contracture. For people at risk due to neuromuscular disease, disability, or prolonged bed rest, four key strategies work together.
First, daily standing or walking. A minimum of two to three hours per day of weight-bearing activity helps maintain lower limb range of motion. For those who can’t stand independently, assisted standing frames serve the same purpose. Second, passive stretching should become a twice-daily routine, ideally morning and evening. Each stretch should be held for a count of 15 and repeated 10 to 15 times per session. This should start as early as possible once a risk factor is identified.
Third, positioning matters during rest. Limbs should be placed in positions that oppose the typical contracture pattern, which usually means promoting extension rather than allowing joints to curl into flexion. Lying face down (prone) is one of the most effective ways to stretch the hip flexors, for instance. Fourth, nighttime splints can maintain range while you sleep. Wrist splints that keep the hand in a gently extended position are commonly recommended, while daytime splints should preserve hand function and sensation rather than locking the joint rigidly.
The overarching principle is simple: joints that move regularly don’t stiffen. The challenge is that the conditions most likely to cause contractures are the same ones that make movement difficult. Starting a prevention program early, before any range of motion is lost, produces far better outcomes than waiting until stiffness has already set in.