Stapelfeldt B, Mornieux G, Oberheim R, Belli A, Gollhofer A
Institut für Sport und Sportwissenschaft, Universität Freiburg, Freiburg, Germany.
Int J Sports Med. 2007 Apr;28(4):326-32. doi: 10.1055/s-2006-924352. Epub 2006 Oct 6.
Determination of pedal forces is a prerequisite to analyse cycling performance capability from a biomechanical point of view. Comparing existing pedal force measurement systems, there are methodological or practical limitations regarding the requirements of scientific sports performance research and enhancement. Therefore, the aim of this study was to develop and to validate a new bicycle instrument that enables pedal forces as well as power output measurements with a free choice of pedal system. The instrument (Powertec-System) is based on force transducer devices, using the Hall-Effect and being mounted between the crank and the pedal. Validation of the method was evaluated by determining the accuracy, the cross talk effect, the influence of lateral forces, the reproducibility and, finally, a possible drift under static conditions. Dynamic tests were conducted to validate the power output measurement in reference to the SRM-System. The mean error of the present system was -0.87 +/- 4.09 % and -1.86 +/- 6.61 % for, respectively, the tangential and radial direction. Cross talk, lateral force influence, reproducibility and drift mean values were < +/- 7 %, < or = 2.4 %, < 0.8 % and 0.02 N x min (-1), respectively. In dynamic conditions, the power output measurement error could be kept below 2.35 %. In conclusion, this method offers the possibility for both valid pedal forces and power output measurements. Moreover, the instrument allows measurements with every pedal system. This method has an interesting potential for biomechanical analyses in cycling research and performance enhancement.
从生物力学角度分析骑行性能能力时，确定踏板力是一个先决条件。比较现有的踏板力测量系统，在科学运动表现研究和提升的要求方面存在方法或实际限制。因此，本研究的目的是开发并验证一种新的自行车仪器，该仪器能够在自由选择踏板系统的情况下进行踏板力以及功率输出测量。该仪器（Powertec系统）基于力传感器装置，利用霍尔效应，安装在曲柄和踏板之间。通过确定准确性、串扰效应、侧向力的影响、可重复性以及最终在静态条件下可能的漂移来评估该方法的有效性。进行动态测试以参照SRM系统验证功率输出测量。本系统在切向和径向的平均误差分别为-0.87±4.09%和-1.86±6.61%。串扰、侧向力影响,可重复性和漂移平均值分别<±7%、<或=2.4%、<0.8%和0.02 N×min(-1)。在动态条件下，功率输出测量误差可保持在2.35%以下。总之，该方法为有效测量踏板力和功率输出提供了可能性。此外，该仪器允许使用任何踏板系统进行测量。这种方法在自行车研究和性能提升的生物力学分析方面具有有趣的潜力。
