Why is joint range of motion limited in patients with cerebral palsy?

Abstract

Patients with spastic cerebral palsy of the upper limb typically present with various problems including an impaired range of motion that affects the positioning of the upper extremity. This impaired range of motion often develops into contractures that further limit functioning of the spastic hand and arm. Understanding why these contractures develop in cerebral palsy will affect the selection of patients suitable for surgical treatment as well as the choice for specific surgical procedures. The generally accepted hypothesis in patients with spastic cerebral palsy is that the hyper-excitability of the stretch reflex combined with increased muscle tone result in extreme angles of the involved joints at rest. Ultimately, these extreme joint angles are thought to result in fixed joint postures. There is no consensus in the literature concerning the pathophysiology of this process. Several hypotheses associated with inactivity and overactivity have been tested by examining the secondary changes in spastic muscle and its surrounding tissue. All hypotheses implicate different secondary changes that consequently require different clinical approaches. In this review, the different hypotheses concerning the development of limited joint range of motion in cerebral palsy are discussed in relation to their secondary changes on the musculoskeletal system.

Muscle-specific changes in length-force characteristics of the calf muscles in the spastic Han-Wistar rat

“…The active lengthforce curve of the spastic GA was narrower and the optimum length was shifted to a shorter fascicle length than in normally developed GA (2, 15, 16). However, estimating length-force characteristics from joint moments can be misleading because this is the net effect of forces exerted by several MTUs and passive structures around the joint, which depend on their moment arms (11,30). Therefore, it remains unclear whether these findings can be attributed to individual MTUs.…”

Upper‐limb contracture development in children with cerebral palsy: a population‐based study

“…Many adolescents and adults with CP exhibit joint deformities with severe, fixed, painful contractures . The occurrence and timing of contracture development in the upper limbs in CP is largely unknown …”

“…1,2 The occurrence and timing of contracture development in the upper limbs in CP is largely unknown. 3,4 Knowledge is lacking about which children with CP are more prone to develop upper-limb contractures, which joints are most commonly affected, and at what age contractures typically occur. Evidence for the effects of treatment of contractures is also lacking.…”

Citizen Scientist: Frank von Hippel’s Adventures in Nuclear Arms Control PART 4. Soviet Nuclear Transparency, the Collapse and After

“…Finally, in 2013, after the cost estimate reached 18 billion USD, the Obama Aministration proposed to scrap the MOX plan and simply dilute the plutonium and bury it in the Department of Energy's deep repository for plutonium-contaminated waste, the Waste Isolation Pilot Plant (WIPP), in New Mexico. Tom Clements, who runs Savannah River Site Watch, a one-man NGO in South Carolina; Ed Lyman of the Union of Concerned Scientists; and I brainstormed with Congressional staff and with the appointee who was leading the plutonium-disposal review in Secretary of Energy Ernest Moniz's 3 office (Clements, Lyman, and von Hippel 2013). The Trump Administration has continued down the track chosen by the Obama Administration.…”