dc.description.abstract | Background: Temporal characteristics and mechanical profiling are two methods that provide a step by step and overall description of running. Recently, a testing and training system (1080 Sprint, Lindingö, Sweden), which not only measures time and distance, but also force, while providing resistance or assistance during running and sprinting became commercially available. This device allows coaches, clinicians and researchers to implement resisted and assisted running in training, rehabilitation and research projects whilst obtaining different physical profiles using only one piece of equipment. The data obtained show a cyclical behavior which can be contributed to individual step mechanics and can be used to study the temporal characteristics of resisted and assisted sprint running. Step, flight and cycle distance as well as other relevant time parameters can be determined. This thesis investigated the validity of measuring temporal characteristics with the system mentioned above.
Methods: Eight subjects (Age: 26 ± 2 years, height: 178 ± 9 cm, weight: 78 ± 10 kg) completed two test days each consisting of 10, 30 m runs with increasing different resistances (1, 3, 6, 9 and 12 kg). The 1080 Sprint provided the resistance and the measurements of time, distance, velocity and force at a sample rate of 333 Hz. Simultaneously, force sensitive resistors (FSR) sensors placed under the insole of each foot were used as criterion for the measurement of contact time.
Results: It was not possible to estimate contact time with the 1080 Sprint, but step time data was successfully estimated. Step time increased as load increased. Compared to FSR sensor data, 1080 Sprint systematically overestimated step time by 2.05 ± 1.08 ms, with a random error of 30.09 ± 4.28 ms.
Conclusion: Our results showed a systematic overestimation of ST of 2.05 ms in the 1080 Sprint when compared to FSR results. The determination of contact times was considered to be unreliable and should therefore not be used. | nb_NO |