Impact of an Orthotic Intervention on Physical Function in Children With Chemotherapy-induced Peripheral Neuropathy

This research study will investigate the effect of two orthotic (brace) devices for the ankle and foot on walking and ankle flexibility in children with cancer not involving the brain or spinal cord. Children undergoing treatment for cancer can suffer from decreased flexibility, strength, balance and endurance from the cancer and from direct effects of the chemotherapy agents. These impairments have been shown to continue years after treatment end, with adult survivors of cancer being less physically active than their siblings. Children, whose chemotherapy includes vincristine, can develop damage to their peripheral nervous system affecting the strength, sensation, and flexibility in their hands and feet. This can then lead to a change in their walking pattern and ankle flexibility and likely contributes to decreased physical activity level and fatigue.

In our clinical practice and pilot work, we know that solid ankle orthotics can be effective in improving gait quality and ankle flexibility. However, in other areas of the country, researchers have published on the effectiveness of using a different type of brace, called a resting night splint, to improve gait and ankle function. Thus, we are studying the comparative efficacy of these two approaches.

Our published pilot study demonstrated that children with cancer were able to wear solid ankle orthotics without an impact on their safety. This study will further the research by comparing the effect of the solid ankle foot orthotic against a resting splint worn at night on walking and ankle flexibility in children with cancer.

Ankle foot orthotics improve a walking pattern by positioning the foot and ankle so that the toe can clear the floor more easily and the child can take a longer step. This decreases the energy needed for a child to walk, allowing the ability to walk longer distances or increase physical activity level. The AFO will also increase ankle flexibility by stretching the muscle while walking. If the child or adolescent walks with an increased step length, they will give a greater stretch to the calf muscles while walking. In contrast, the resting night splint can increase ankle flexibility by providing a gentle stretch to the calf muscles while sleeping, therefore allowing improved ankle movement when walking and a longer step length. We will examine the impact of these orthotics on walking, ankle flexibility, ankle strength, aerobic capacity, self-reported fatigue, as well as the ability of the children to wear the orthotic as prescribed and the severity of the damage to the nervous system.

Children and adolescents who are found to have ankle weakness, ankle tightness, and damage to their peripheral nervous system as a result of cancer treatment will be referred to the study by the treating physical therapist (PT). The PT will contact the investigators and they will invite the child or adolescent to participate in the study. Using previously established measurements in children with cancer, we will measure walking pattern, ankle strength, ankle flexibility, foot posture, level of physical activity, and level of fatigue prior to the orthotic intervention. The subject will then be randomized between an 8-week AFO or RNS intervention. The orthotic will be made with a small temperature sensor that will collect data on wearing time of the brace. After 8 weeks of orthotic wear, we will repeat the measurements and compare results between the two orthotic types.