The patient underwent 2 separate 3-dimensional gait analyses in a motion analysis laboratory. The kinematic data were acquired using an 8-camera Vicon 612 (Vicon, Oxford, United Kingdom) 3-dimensional motion analysis system. Data were filtered and processed using Vicon Workstation software (version 5.2.9), with averaged graphs generated using Vicon Polygon software (version 3.1). The Vicon system uses a set of reflective markers affixed to the skin over specific bony landmarks of the pelvis and lower extremities. Kinematic markers were fixed with double-sided tape and placed bilaterally over the anterior superior iliac spine, the point midway between the 2 posterior superior iliac spines, the lateral epicondyle of the femur, lateral shank, lateral malleolus, and heel, and between the distal second and third metatarsal head. Markers were placed as accurately as possible to minimize interference from the TheraTog garment or the pelvic strap of the TCs. When necessary, locations of the pelvic bony landmarks were palpated and markers were placed in the approximate locations on the outside of the garment. An experienced motion laboratory physical therapist (19 years in this motion laboratory) applied the markers, obtained measurements, and reviewed the gait data for both tests. The patient took several walks at a self-selected speed, down a 15-m path with 1 hand-held by the parent, because of her young age and limited attention to the task. Sagittal, coronal, and transverse plane joint motion data were collected for the pelvis, hips, knees, and ankles. Data from 7 to 10 strides for each side under each condition were averaged and used in the gait analysis report. The computerized analysis was completed by the Motion Analysis Laboratory biomedical engineer.
At the end of each intervention trial, the parent submitted the wearing log to the therapist and completed a parent satisfaction survey that had been used in a previous TheraTog study.5 This survey uses a 5-point Likert Scale to document the parent's overall satisfaction with the ease of use and perception of effectiveness of either TheraTogs or TCs.
DESCRIPTION OF OUTCOMES
As this report involved a single case, the data collected were interpreted for clinical significance rather than statistical significance. Although 3-dimensional data were obtained from all joints, the kinematic gait parameters that were examined for this particular report included average foot progression in stance, maximum knee extension in stance, and average hip rotation in stance (Table 1). Hip rotation and foot progression were selected since they were the parameters that should be directly affected by the orthoses. Knee extension in stance was also selected because it showed marked differences between conditions.
At baseline with AFOs alone, the participant exhibited slight knee flexion bilaterally during stance with the right lower extremity greater than the left by 8˚. Hip external rotation was observed bilaterally with the right greater than with the left. Internal foot progression was noted bilaterally in the stance phase of gait, more on the left than on the right (Table 1).
During ambulation with TheraTogs and AFOs, knee flexion in stance was increased to an excessive amount bilaterally. Hip external rotation was increased bilaterally, especially on the left lower extremity. The participant demonstrated more external foot progression than normal on the right lower extremity, while decreasing internal foot progression of the left lower extremity compared with the baseline AFO condition (Table 1).
The greatest changes in kinematic data from the baseline condition were seen during gait with TCs and AFOs. With the TCs, the participant had knee extension values approximating the typical reference standard (RS) bilaterally. The hips remained in external rotation during stance with TCs, but values were less than those with TheraTogs. The patient had increased right external foot progression (closer to the RS value) in comparison to ambulation with AFOs alone; however, this was less than with TheraTogs and AFOs. In the left lower extremity, there was a greater decrease in internal foot progression than with TheraTogs (Table 1).
In addition to the kinematic data, gait temporal-spatial characteristics were examined in each bracing condition. These included velocity (meters per minute), cadence (steps per minute), stride length (meters), and double-limb stance (initial + terminal stance phase of gait). Gait characteristics were expressed in absolute values as well as a percentage of RS values for the subject's age (Figure 3). At baseline with AFOs only, the subject's gait velocity was 72% of the RS, less than typical for her age because of a decreased cadence. In both of the other conditions, the subject's gait velocity decreased versus the baseline condition, although substantially more with AFOs and TCs than with AFOs and TheraTogs (67% and 56% of the RSs, respectively). With TheraTogs, the decline was largely due to decreased stride length (82% of the RS), whereas with TCs it was due to decreased cadence (59% of the RS) (Figure 3). Although the subject spent a larger percentage of time than typically expected in double-limb stance (176% of the RS) at baseline (indicating instability), she presented with a greater increase in double-limb stance with both AFOs and TheraTogs (196% of the RS) and AFOs and TCs (207% of the RS) (Figure 3). Of note, the weight of TCs with AFOs was 0.7 kg, 5% of the subject's body weight, and the weight of TheraTogs with AFOs was 0.3 kg, 2% of the subject's body weight.
Parent satisfaction with TCs and TheraTogs was measured with a survey using a 5-point Likert scale, with 1 = strongly agree and 5 = strongly disagree (Table 2). Scores indicated that her mother preferred TheraTogs greatly over TCs. She indicated that she was very pleased with the ease of donning the TheraTogs, and with how the subject tolerated wear. Her survey after the use of TCs indicated that the subject did not tolerate wearing them well and did not walk well when wearing them. She was able to wear the TheraTogs an average of 8.5 hours a day, whereas she wore the TCs an average of 15 minutes per day.
In this case, external rotation of both lower extremities was achieved with both TheraTogs and TCs, helping correct in-toeing gait measured dynamically through foot progression. The difference between the interventions was the source of the external rotation. TheraTogs corrected in-toeing by excessively externally rotating the hips. The values for hip rotation with the use of TCs were closer to RS (less excessively external) than with the use of TheraTogs, indicating that improved foot progression with TCs was achieved by rotating the lower leg with respect to the thigh via the knee joint. Since TheraTogs caused external rotation at the hip instead of the knee, their use may actually decrease the stress through the knees and prevent future knee problems such as ligamentous instability, arthritis, and pain, which are common in the older SB patient population.3 A slight overcorrection of foot progression on the right and an undercorrection on the left was seen with the TheraTogs, which may be related to the strapping technique. The strapping technique used in our intervention involved wrapping a strap around the posterior aspect of the lower thigh, which had the effect of flexing the knee in stance phase. Excessive knee flexion during gait in children with myelomeningocele is associated with knee pain later in life3 and should be prevented if possible. After the intervention was completed, the mother was instructed in an alternative strapping technique, which improved knee position in stance by passing the strap in front of, rather than behind, the distal thigh and knee. Although flexibility of application is a significant advantage to TheraTogs, education is needed for the parent in the correct strapping technique. Variability of application is not an issue with TCs as they are set in the optimal alignment determined by the orthopedist and the orthotist. There is less potential for errors in application of TCs since they are attached directly to AFOs. The only potential for variation is in the tension with which the pelvic strap is fastened, which, if too loose, may allow pelvic rotation.
The increased knee flexion in stance phase seen during ambulation in TheraTogs decreased the subject's stride length. In spite of this, her gait velocity was closer to the baseline condition than with TCs due to higher cadence. Stride length was greater with the use of the TCs than with the use of TheraTogs, but cadence may have been limited by their weight. Overall, the TCs allowed temporal-spatial values that more closely approximated RSs for gait.
The parent of our subject indicated her strong preference for TheraTogs in the satisfaction survey. In additional comments, she stated that she preferred the appearance of TheraTogs and felt that they were easy to don and use. The subject did not tolerate TCs well, which significantly decreased her compliance with wear. TheraTogs are lightweight in comparison with TCs, which may partially explain the patient's ability to wear them for longer periods than TCs. The parent also felt that the subject walked better overall with TheraTogs, even though the gait analyses indicated better kinematic data with TCs.
Limitations of this case report include involving a single subject, so that the results cannot be generalized to the intended population. The patient had no prior experience with either device, and because of logistical constraints, she used TheraTogs first. It is possible that both the child's and the parent's acceptance of TCs may have been different if they had been used first. Because of the configuration of TCs, kinematic knee markers had to be placed on the outside of the brace, which may have affected the kinematic data obtained. The intervention time for both TheraTogs and TCs was relatively short, but evidence to support ideal wear time is not available in the literature at this time. Future studies should include patients with varied levels of SB and standardized wear time for TheraTogs. Finally, identification of characteristics, such as neurosegmental level, of patients who benefit most from the use of TheraTogs would be useful.
In this case report, correction of in-toeing due to excessive internal tibial torsion was achieved with both TheraTogs and TCs. Use of TheraTogs decreased in-toeing by excessively externally rotating the hips, whereas TCs affected foot progression through external rotation at the knee. In this case, TCs corrected in-toeing more effectively, but the subject and her parent showed a strong preference for TheraTogs. Although TCs were more effective, it is possible that equivalent correction of in-toeing could be achieved in smaller, younger children with the use of TheraTogs. This is accomplished through strapping techniques that are individually tailored to the child's specific alignment.
Clinicians need to consider if the site of derotation (hip vs knee) is imperative in decreasing in-toeing in SB, or if improved alignment of the foot with increased compliance is the goal. TheraTogs were effective in management of in-toeing for this subject with her specific level of innervation, height, and weight. Therefore, TheraTogs may be a viable option for correcting in-toeing in children with SB. Further research is needed to determine the anthropometric measures and level of function for which TheraTogs application would be the most successful.
We thank Lerman and Son Orthotics and Prosthetics for its contribution of the AFOs and TCs for the intervention.
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Keywords:© 2012 Lippincott Williams & Wilkins, Inc.
child/preschool; female; gait; orthoses; patient preference; spina bifida cystica