Presenting Author:

Theresa Sukal-Moulton, D.P.T.

Principal Investigator:

Theresa Sukal-Moulton, D.P.T.

Department:

Physical Therapy and Human Movement Sciences

Keywords:

selective voluntary motor control, leg, lower extremity, cerebral palsy, children, strength

Location:

Ryan Family Atrium, Robert H. Lurie Medical Research Center

C106 - Clinical

Pilot study of lower extremity isometric joint torques in children

Background/Objectives:It is well agreed upon that there is both a lack of strength and loss of independent joint control in the lower extremities of those with cerebral palsy (CP), likely due to damage to corticospinal tracts. Currently, there are clinical options for measuring selective control using observational measures, and strength can be quantified at certain joints with hand held dynamometry. Stabilization for these measures can be very challenging, however, particularly when atypical patterns of movement prevent patients from isolating effort to a single joint. Furthermore, the most functionally relevant position to understand impact of these motor impairments on function is standing, but balance challenges make this impossible for many patients. The ability to fully characterize the output of the neuromuscular system allows for more mechanistic investigations to further understand the source and nature of atypical motor output in CP. Importantly, the results may differ between unilateral and bilateral injuries which has not been well studied to date. The objective of this poster is to describe the device and provide examples of its use in the study of neuromuscular disorders, compared to typically developing children. Description: A custom isometric device was designed and used to study the lower extremity joint torque coupling patterns and abilities in adults following a stroke. Importantly, the use of two 6 degrees-of-freedom load cells gives the ability to simultaneously measure efforts at the hip, knee and ankle. This can be accomplished in an upright posture while removing the need to balance or support one’s self by supporting the pelvis and trunk in a way that does not allow for compensations. This poster will demonstrate the device, show the changes that have been made to modify the original device for use with children, and describe the methodology to collect data. Pilot results from 12 children, ages 8-12 years, will be shown to give insight to the type of information that can be ascertained from the assessment. Significance: Besides giving more precise measurement of maximal joint torque production or ability to isolate activity to a particular single joint or direction of effort, this device provides the opportunity to measure or train individuals to combine joint torques in specific ways, for example simultaneously generating hip abduction and knee extension torques needed for a smooth transition from sit to stand. Although the device has been used with CP, there would be opportunity to extend to other childhood-onset diagnoses where the coordination of lower extremity is of clinical and scientific importance.