Reaction Force Measurement in Milwaukee Brace during Daily Activities-Introduction of a New Measurement System

Abstract

Aims: The reaction forces of the Milwaukee Brace’s (MB’s) several areas were measured during normal daily activities (24 hr) by a new measurement device improved in order to force acquisition by groups of sensors distributed in all of the MB’s internal areas. Methodology: In the current study, a new measurement system using Force Sensitive Resistance (FSRs) distributed on the different areas of MB for scoliosis patients. Sensitivity analysis has been fulfilled to compare two different sensors arrangements placed in the basket of MB. A reliability analysis has been carried out for normal activities including sitting, walking and sleeping. Two healthy volunteers and two scoliosis patients were nominated to force acquisition from their MB during 23 hours of daily activities. Results: In the sensitivity analysis, maximum value of Cronbach’s Alpha was 0.775 for sitting at basket lateral side. In the reliability analysis, the maximum and minimum difference between the force values of the two arrangements is 1.37(N) and 0.19(N) respectively related to the sitting test. The tests for each subject commenced with 9-11 hours of sleeping and continued for 12-14 hours in which main activities were sitting and walking. The forces average values of each part of the tests were reported for different areas of MBs. The mean, median, mode, standard deviation and ratio of standard deviation on the mean have been calculated for each brace region for both time durations. Conclusion: The brace different areas forces for sleeping and day time activities had normal distribution. The force value of the brace regions having direct contact with mattress surface was increased during sleeping with respect to day time activities. Other regions forces were decreased or remained constant in this time duration. The forces detected from the lumbar pad during most of the test time were constant.