| Description |
Kneeling is a daily activity for some occupations like carpet layers, miners, tile layers, floor layers, electricians, shipbuilders and many others. Several studies have shown that there is an association between kneeling or squatting and development of osteoarthritis of the knee joint. Even though this relationship has been established, few research studies have been conducted to estimate actual knee stresses and the role of kneepads in reducing these stresses while kneeling. Hence, this study looks at estimating the stress on the knees during simulated kneeling work while wearing six different types of kneepads. Custom force sensors were fabricated using FlexiForce™ Sensors and were placed on both knees over anatomically defined landmarks on the patella and tibial tubercle. Ten participants were recruited and consented to perform a series of kneeling tasks. Five wooden platforms were placed in five different locations surrounding two force plates and custom made three-axis load cells where the participants knelt. A set of five lettered, ceramic tiles were given to each participant and randomly placed on each platform with a corresponding letter. Estimated kneeling reaction forces derived from sensor values were used to quantify the effectiveness of each design in reducing the applied forces on the knee joint. Also these forces were used to verify the significance of location on force. The data from both the sensors and the force plates and load cells were analyzed for results. Two-way analysis of variance (ANOVA) with repeated measures, where kneepad and location were the independent variables and calculated applied force was the independent variable was used to analyze the results. There was a significant relationship between force and kneepad and also between force and location. The placement of the sensor on the knee was found to be a major factor for the estimation of the force on the knees. It is apparent that proper kneepad design and selection can be an effective abatement to reduce the stress accumulated on the knee during kneeling work. |
