To evaluate whether continuous training and education of posture can help children to improve kyphosis. A smart harness consisting of a tight-fitting harness and a posture sensing system was developed to measure kyphosis and to provide vibratory feedback during daily activities. The posture sensing system consisted of two sensor units and both units contained a 3-axis accelerometer and a 2-axis gyroscope to calculate the orientation. The dimensions and weight of each unit were 55 mm x 35 mm x 15 mm and 25g, respectively. One unit served as a master (placed at the T3 vertebral level) and the second unit served as a slave (placed at the T12 level) and they communicated wirelessly. The master unit calculated the kyphotic angle, similar to the vertebral centroid method but based on the sagital profile, and provided the vibratory feedback. One volunteer wore the unit and performed different postures and activities (walking, sitting, bending and sudden change from sitting to walking) in a gait analysis laboratory. The posture sensing system was sampled at 30Hz and a gait analysis 8-camera system was sampled at 60Hz. The kyphotic angles captured by the smart harness and camera system were compared. After this validation, the system was tested by 5 normal subjects (M, 25 10 years old) 3 hours per day for 4 consecutive days. For the first 2 days there was no feedback and the last 2 days there was feedback. The system took a sample every 30 seconds. When an undesirable posture was detected, the system switched to a fast sample mode at which time the system took ten measurements with a sample rate of 10 Hz for 1 second to further validate the measured kyphotic angle. These 10 measures were averaged to avoid feedback for postures that lasted only for a very short period of time. Posture orientation data was stored in the sensing unit memory and downloaded for outcomes evaluation.Purpose
Method
To correlate the initial brace correction with quantity and quality of brace wear within the first 6 months for the treatment of adolescent idiopathic scoliosis (AIS). Brace treatment for AIS has been debated for years. Prediction of treatment outcomes is difficult as the actual brace usage is generally unknown. As technology became more advanced, electronic devices were able to measure adherence in both quantity (how much time the brace has been worn) and quality (how tightly the brace has been worn) of brace usage without need for patient interaction. The developed adherence monitor consisted of a force sensor and a data acquisition unit. Subjects were monitored within the first 6 months of brace wear. The data sample rate was set to be one sample per minute. Data was downloaded at the patients routine clinical visits. The prescription, first in-brace and first follow-up out-of-brace Cobb angles were measured. Twelve AIS subjects (10F, 2M), age between 9.8 and 14.7 years, average 11.9 1.5 years, who were prescribed a new TLSO and full-time brace wear (23 hours/day) participated. All braces were made by the same orthotist. The force value at the major pressure pad at the prescribed tightness level was recorded as the individualized reference value. The normalized force value (measured force magnitude relative to the individualized reference value) was used for the quality factor. The time of brace usage relative to the prescribed time was used as the quantity factor.Purpose
Method
Brace correction based upon mechanical action requires appropriate interface pressure between the body and the brace. A smart orthotic was developed to record how much time (quantity) a brace was used, how well (quality) it was used and maintain the interface pressure to the prescribed level. Six subjects were recruited and they all used Boston style braces. Each subject used the system for two weeks without the force maintenance system activated to serve as the control period, and the remaining two weeks with the force maintenance system activated. During the automatic feedback mode, the pressure maintenance system was activated only during the daytime (8:00–22:00hrs) to avoid disturbing the patients during sleep. The subject could either return the system to us after one month or continue to use the system until the next clinic. The time that the pressure level was in the target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. The average brace wear time for the study period was 72 +/− 15% (12.6hr/day) of the prescribed time (17.5 +/− 3.8 hours). The curve severity of all subjects on the following clinical visit was the same (within measurement error) as the first visit (32 +/− 5 vs 31 +/− 5 degrees). Compliance was not affected when wearing the monitor. The smart orthotic was able to improve the efficiency of a conventional brace by maintaining the prescribed interface pressure automatically. This proposed work helps brace candidates wear their braces more effectively and gets the most benefit from the brace treatment. As a result, all participated subjects maintained their Cobb angle within ± two degrees during the study period.
The efficiency of brace treatment for adolescent idiopathic scoliosis is correlated to how the brace has been worn. A smart orthosis was developed to maintain the interface pressure between the brace and the body within the prescribed range during daily activity. Six patients with scoliosis, with Cobb angles of 31 +/− 5 degrees, who were new brace candidates were recruited. They used the system for four weeks: two weeks with monitoring only and two weeks with an automatic feedback activated. The time that the pressure level was in target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. This work helps brace candidates wear their braces more effectively and receive the most benefit from the brace treatment. As a result, all subjects who participated in the study maintained their Cobb angles within + two degrees during the study period. Brace correction based upon mechanical action requires appropriate interface pressure between the body and the brace. A smart orthosis was developed to record how much time (quantity) a brace was worn, how well (quality) it was used and how well the interface pressure was maintained to the prescribed level. Six subjects were recruited and they all were fitted with Boston style braces. Each subject wore the brace for 2 weeks without the force maintenance system activated to serve as the control period, and the remaining 2 weeks with the force maintenance system activated. During the automatic feedback mode, the pressure maintenance system was activated only during the daytime hours (8:00–22:00hrs) to avoid disturbing the patients during sleep. The subject could either return the system to us after 1 month or continue to use the system until the next clinic. The time that the pressure level was in the target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. The average brace wear time for the study period was 72 +/− 15% (12.6hr/day) of the prescribed time (17.5 +/− 3.8 hours). The curve severity of all subjects on the following clinical visit was the same (within measurement error) as the first visit (32 +/− 5 vs 31 +/− 5 degrees). Compliance was not affected when wearing the monitor. The smart orthosis was able to improve the efficiency of a conventional brace by maintaining the prescribed interface pressure automatically. This project helps brace candidates wear their braces more effectively and gets the most benefit from the brace treatment. As a result, all participating subjects maintained their Cobb angle within +/− 2 degrees during the study period.
To determine the pattern of brace wear compliance over time in both day and night time wear by using objective force measurements within the brace. Twenty subjects who were diagnosed of AIS, age between nine and fifteen years, and new to brace treatment were recruited in this study. To use the data for analysis, only subjects who used the brace for five hours continuously either in daytime or nighttime were considered. For daytime wear, the selected five hour intervals had to begin with an initial spike in force after a period of non-activity as recorded by the transducer, which would indicate that they had just put on the brace. At night, the measurements began at one am and ended at six am. Among the twenty subjects, only nine subjects’ data were used for daytime and eleven subjects’ data were used in nighttime. The average wear period was 11.4 ± 4.3 days for the day group, 11.6 ± 3.9 days for the night group. There was a statistically significant decrease in force within the first five hours of consecutive brace wear during daytime hours. The decrease was from 1.4 ± 0.6 (140% of prescribed force) in the first hour to 1.0 ± 0.6 in the fifth hour, a difference of 0.4, which is a 29% drop from the initial force. Most of the drop in force happened between hour one and hour two, as the difference in those two hours is 0.2 ± 0.1 (p = 0.001); between hours two and five the difference did not reach statistical significance. The observed difference between hours one and five for the night group was 0.2 ± 0.2, p = 0.06, which did not reach significance as well. Daytime forces in a Boston Brace tend to decrease over a period of time, but the nighttime forces seem to be maintained at the same level. These results show that daily adjustment of the brace tightness may be required to maintain the tightness level and the efficiency of brace treatment.
Introduction: Braces are the most generally accepted form of non surgical treatment for adolescent idiopathic scoliosis (AIS). Despite decades of usage controversy still exists regarding the efficacy of this treatment. We believe this controversy continues in part because there are few studies describing the mechanical effect of bracing and linking mechanically effective bracing to changes in the natural history of AIS. If braces are effective, is it because they apply significant mechanical support to a collapsing spine or are they effective for other reasons? A first step towards answering this question is to document the mechanical action of braces during activities of daily living. This would enable researchers to examine the effect of mechanical support on progression of the scoliosis. The objective of this study was to determine the temporal pattern of forces exerted by the pressure pad in Boston braces prescribed for the treatment of AIS. Methods and results: A force transducer and a programmable data logger were designed to measure loads exerted by the pressure pad over extended periods of time. The loads were recorded at one minute intervals. Braces were adjusted to a prescribed load level and the patients were asked to set the brace tightness to match this target any time the brace was donned. Brace wear data were stratified into: not worn, worn at less than 80% of target, 80–120% of target and greater than 120% of target. Bracing was considered mechanically effective if the load was at least 80% of the prescribed level. Patients were aware of the study and consented to participate. Thirteen patients were followed from 1 to 16 days, average was 9±5 days. Nine patients were asked to wear their braces 23 hours per day, two for 20 and two for 16 hours per day. Braces were not worn 34±27% of the time logged. When they were worn, patients adjusted the tightness of the brace such that it was <
80% of the target 29±20% of the time, within 20% of target 19±19% and over 120% of target 18±13% of the time. Patients wore their braces at or above the target levels 33% of the time logged or 8 hours in a typical day. Subjects had no difficulties using the data logger and none complained that it interfered with brace wear. Reviewing individual histories suggested that subjects did not alter their brace wear pattern because of the data logger. Conclusion: The mechanical effectiveness of the brace varies considerably over the normal course of wear but seldom does it provide the support intended. While patients wear their braces for about 16 hours per day, it is mechanically effective for 8 hours only.