Loading rate patterns in scoliotic children during gait: the impact of the schoolbag carriage and the importance of its position.

PURPOSE: Concerns have been raised regarding the effects of schoolbag carriage on adolescent schoolchildren and particularly those with a pre-existing spinal deformity. The purpose of this study was to determine the effect of school backpack loads in scoliotic and healthy school-age children during walking, in terms of peak vertical ground reaction forces and loading rates. We hypothesized that walking with a loaded backpack would have a greater effect on gait kinetics of scoliotic compared to healthy. METHODS: Eight children with idiopathic scoliosis and eight healthy children were assessed. Kinetic data were collected using two AMTI OR6-7 force-plates, while the subjects walked freely along a 6-m walkway under three walking conditions: (1) without a schoolbag, (2) carrying a schoolbag bilaterally (over both shoulders-symmetrical load) and (3) carrying a schoolbag unilaterally (over each shoulder-asymmetrical load). Kinetic data were collected and four parameters were calculated; peak ground reaction force at the first maximum force peak (F1), time needed to reach F1 (T1), loading rate of F1 (LRF1) and total contact time (T2). RESULTS: We found no significant differences between the scoliotic and healthy children for any of the kinetic variables examined. In addition, the position of the bag did not seem to have any effect on loading rate. CONCLUSIONS: The results of this study indicate that in terms of kinetic parameters during normal gait, the schoolbag load (symmetrical or asymmetrical) does not have a different effect on children with mild adolescent idiopathic scoliosis compared to normal controls.

A cheap telemetric system for analyzing gait.

This study presents a technique for gait analysis, developed for the assessment of footfall timing and speed. The system in question consists of a transmitter, a receiver, a conductive walkway and a PC with the appropriate software. The technique was first tested for accuracy and repeatability with known signals, and was validated with a group of 20 healthy male adults (mean age = 34 years, S.D. = 5.5). The results thus obtained were similar to those reported in the literature for corresponding groups. Then, measurements on 10 children suffering from cerebral palsy (spastic hemiplegia) were performed. Gait analysis was carried out just before surgery and one year post-operatively. The results confirm the validity of the technique for measurements on orthopedic patients and its efficiency for functional evaluation of gait improvement after surgery.

Temporal gait analysis of hip osteoarthritic patients operated with cementless hip replacement.

OBJECTIVE: This study attempts to identify temporal gait parameters, which characterize the pre- and postoperative course of hip monoarthritic patients who undergo cementless hip replacement. BACKGROUND AND METHODS: Twenty-five female hip monoarthritic subjects (mean age 51, SD 5.0) were studied preoperatively; 20 out of them were studied at 1 and 8-10 years after the operation with a 22-m conductive walkway system using telemetry. A gender-matched control group was also studied (mean age 60, SD 2.0). The assessed parameters are the gait cycle duration, the single and double support, the single step duration and the gait speed. RESULTS: The results indicate that improvement in patients' conditions following the operation occurs rapidly during the first postoperative year. Yet the hip has not reached optimal performance 1 year postoperatively; 8-10 years later it seems to have reached its optimal performance and remains in good condition. However, it still is below that of the controls. CONCLUSIONS: Single support duration and speed are crucial in characterizing the functional restitution of patients after hip replacement. RELEVANCE: An orthopaedic surgeon who attempts to quantify the postoperative course of hip monoarthritic patients after cementless hip replacement can focus at those temporal factors, which are typical of the functional restitution after the operation, without losing any valuable information given by other values.

Active plantar-flexion above-knee prosthesis: concept and preliminary design.

Lower limb prostheses produced so far do not replace the function of the musculature, which provides the necessary amount and the proper distribution of energy to the ambulatory mechanism. Provision of external power to lower limb prostheses has been hindered by the fact that the large amount of energy needed at a lower limb necessitates the use of external power sources of unacceptably high mass and volume. Self energized mechanisms offer a promising alternative to the problem. Normally a large part of energy output during locomotion appears at the ankle joint. It seems therefore desirable to develop an above-knee prosthesis featuring active plantar-flexion at the ankle. Energy may be offered by a self energized system. The system, described here, accumulates energy during the passive movements of the knee and ankle joints and stores it for later use at the ankle.

A conductive walkway system for measurement of temporal and distance parameters of gait.

This work describes a system used in gait analysis studies. The system is based on a continuous conductive walkway, made of ordinary aluminum foil. It measures the length of each single step, as well as those temporal parameters of gait that relate to the position of the feet on or off the ground. The system is relatively simple and inexpensive to build and run. Data collection and reduction is not excessively time consuming and does not require particularly high training of the operator. In conjunction with a microcomputer the system could be suitable for routine testing in the clinical environment. The present setup has been tested and proved consistent and sufficiently accurate.

Spatial parameters of gait related to the position of the foot on the ground.

A number of parameters related to the position of the foot on the ground during normal level walking were analysed for a group of young and a group of old subjects, divided in two sub-groups each, according to sex. The analysis has shown asymmetries between the left and the right side of a number of subjects, differences between sexes and differences between age groups. Changes in the parameters of gait for the old subjects served the task of providing a larger base of support and a smaller loading of the hip musculature.

A portable system for the measurement of the temporal parameters of gait.

An easy-to-use, low cost, portable system is presented. It consists of a transmitter, four electrical sensors, a receiver and a PC with the appropriate software. The system can assess footfall timing, that is the single limb support, double limb support, single step duration values, and the gait cycle duration. This system has been tested for its accuracy with known signals. Then, measurements on a group of twenty (20) healthy adults were performed, with statistically insignificant (p>0.2) results to those reported in the literature. The above prove the system's validity for temporal gait analysis.

p53 and c-jun expression in urinary bladder transitional cell carcinoma: correlation with proliferating cell nuclear antigen (PCNA) histological grade and clinical stage.

OBJECTIVE: To investigate p53 and c-jun oncoproteins and proliferating cell nuclear antigen (PCNA) in transitional cell urinary bladder carcinomas (TCCs) and to determine their relationships to tumour grade, stage and survival. MATERIALS AND METHODS: The expression of p53, c-jun and PCNA was studied using immunohistochemistry in formalin-fixed, paraffin-embedded tissues in a series of 110 TCCs. RESULTS: 58% of our cases were positive for p53 and 88% for c-jun. A statistically very significant correlation (p < 0.0001) was observed between p53 and c-jun (r = 0.781), p53 and PCNA (r = 0.772), c-jun and PCNA (r = 0.831) as well as between each of the two oncoproteins and the histological grade and clinical stage (p < 0.001). There was no correlation of either p53, PCNA or c-jun with clinical outcome in terms of patients survival. CONCLUSION: p53 and c-jun proteins' overexpression are strongly related to rapid tumour cell proliferation and hence with aggressive growth in urinary bladder TCC. PCNA score remains an important prognostic index in transitional cell carcinoma of the bladder.

Biphasic radiosensitization of human lymphocytes by diethyldithiocarbamate: possible involvement of superoxide dismutase.

A biphasic radiosensitization of human lymphocytes by diethyldithiocarbamate (DDC), a metal chelator, was observed. The first phase occurred at 10(-5) M and the second at 10(-3) MDDC. The biphasic radiosensitization coincided with the previously reported biphasic toxicity of DDC. Inhibition of superoxide dismutase (SOD) occurred only in the second phase, suggesting that it may be a contributing cause of this phase. The mechanism of the first radiosensitization phase is not known. The radiation survival curves indicated the presence of at least two lymphocyte populations differing in their radiosensitivity and representing 40 per cent and 60 per cent of the cells. Both cell populations were biphasically radiosensitized by DDC.