Date of Paper/Work


Type of Paper/Work

Research Project

Degree Name

Doctor of Physical Therapy (DPT)


Physical Therapy

First Advisor

David D. Chapman


BACKGROUND AND PURPOSE: Current literature regarding the leg movements and kicks of infants with Spina Bifida (SB) is limited. Kicking reflects the motor development of the lower extremities, which influences the emergence of walking. The purpose of this study was to investigate the type and frequency of spontaneous and goal directed leg movements and kicks through the use of conjugate reinforcement in infants with SB.

METHODS: The spontaneous leg movements of five infants with lumbar or sacral SB were videotaped while supine: untethered (baseline); tethered to an overhead mobile (acquisition); and untethered (extinction). Data collection took place in each infant’s home when the parents reported their baby was generally alert and active. Anthropometric measures were collected to determine if selected traits (eg thigh length) were related to the frequency of leg movements and kicks generated by the babies. Frame by frame behavior coding was used to identify leg movements and kicks.

RESULTS: All five infants moved their tethered leg more than their untethered leg in the acquisition condition. Participants generated significantly more leg movements in the acquisition or extinction condition compared to baseline (p = 0.014). The babies also generated more total kicks in the acquisition or extinction condition compared to baseline, but this was not significant (p = 0.124). Each baby responded uniquely to the conjugate reinforcement paradigm with respect to the frequency and types of kicks she generated (ie alternating leg kicks). There were non-significant, but moderate - high correlations between selected anthropometric measures (eg calf and thigh length, lower extremity range of motion) and leg movements and kicks.

CONCLUSION: These babies increased how often they moved their legs and kicked as a result of experiencing the mobile paradigm. Beyond frequency of leg movements and kicks, each baby demonstrated an individual response to the conjugate reinforcement paradigm by increasing the number of complex kicks she generated or demonstrating new types of kicks in the acquisition or extinction conditions compared to baseline. Clinically, the conjugate reinforcement paradigm provides babies with SB increased opportunities to strengthen their leg muscles and the neuromuscular connections that support kicks.