Browsing by Author "Groeneveld, Llewellyn Wallace"
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- ItemMeasurement of in vivo patella and achilles tendon forces during treadmill running(Stellenbosch : Stellenbosch University., 2020-03) Groeneveld, Llewellyn Wallace; Muller, Jacobus Hendrik; Schreve, Kristiaan; Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering.ENGLISH ABSTRACT: Tendons are the connections that translate forces from muscles to bone and are essential to the musculoskeletal system movement during locomotion. The load experienced during running is believed to be a primary injury factor for tendinopathy (Malliaras et al., 2015). An individual’s running biomechanics influence the load experienced, and are risk factors for both Achilles (Chang et al., 2000; Moore et al., 2014; Moore et al., 2016) and patella (Kunimasa et al., 2014) tendinopathy. This study investigated the feasibility of using a fibre optic sensor to measure in vivo patella and Achilles tendon forces during running. The study also aimed to determine whether the sensor could detect differences in tendon loads as a function of intrinsic and extrinsic factors in running conditions. According to the author’s knowledge this was the first time a fiber optic sensor was used to measure tendon force during running. A light intensity based fibre optic sensor system capable of measuring in vivo tendon forces was designed, built and tested. The sensor was implemented in a pilot study with five participants to measure in vivo tendon forces during treadmill running tests while simultaneously measuring the muscle activity, kinematics and kinetics. The tests were conducted at the Neuromechanics Unit of Central Analytical Facilities at Stellenbosch University. The optic fiber was inserted into the patella and Achilles tendon by a surgeon with guidance of an ultrasound. The instrumented running tests consisted of six tests at variable conditions: level running at self-selected speed and stride frequency, level running at 110% stride frequency, level running at 90% stride frequency, level running at 10 km/h, 9% incline at 10 km/h and 9% decline at 10 km/h. The Achilles and patella tendon moment arms were determined using a scaled OpenSim model (Rajagopal et al., 2016). Attempts were made to calibrate the sensor, however these were considered to be inaccurate. Despite thereof, the sensor enabled detection of proportional changes in tendon force for quantitative comparison between running conditions. A fibre optic sensor can be used to measure in vivo patella tendon forces during running on an instrumented treadmill. The measurement of the Achilles tendon forces were difficult due to breakage of the fibre during the running tests. The breakage of optic fiber could be due to the high cyclic loading of tendons during running and influenced by a participants ground reaction force and height. The fibre optic sensor could also detect differences in tendon loads caused by intrinsic and extrinsic changes in running conditions. The running conditions that decreased peak tendon forces were the inclined and declined conditions for the Achilles tendon, and the increase in stride frequency and inclined conditions for the patella tendon. The sensor was found to affect a participant’s biomechanical parameters during running, for some of which of the effect sizes were substantial. It remains unclear how this should be accounted for in clinical interpretation of results, thus warrants further investigation.