Musson C, Kramer M
Human Movement Science Department, Nelson Mandela University, Gqeberha, South Africa.
Physical Activity, Sport and Recreation (PhaSRec) Unit, Human Movement Sciences Department, North-West University, Potchefstroom, South Africa.
S Afr J Sports Med. 2021 Apr 21;33(1):v33i1a9483. doi: 10.17159/2078-516X/2021/v33i1a9483. eCollection 2021.
Swimming is a multifaceted sport with nuanced performance parameters that tend to vary according to the swimmer's stroke style. The extraction and analyses of swim parameters, such as lap time (LT), stroke length (SL), stroke rate (SR) and velocity are time-consuming. This may be eased and to some extent automated by the use of cost-effective tri-axial accelerometers.
To determine the validity of tri-axial accelerometers across all four stroke styles, and to investigate kinematic differences in stroke styles using accelerometer-based data.
Twelve elite swimmers were recruited for the study. The group consisted of five male (age: 22.2 ± 2.6 years; height: 1.84 ± 0.08 m; weight: 76.2 ± 3.6 kg) and seven female (age: 20.7 ± 2.1 years; height: 1.68 ± 0.08 cm; weight: 62.0 ± 6.3 kg) swimmers.
There was a small but significant bias for accelerometery data compared to video data across most parameters and stroke styles except for stroke length and stroke count (p > 0.05). However, accelerometery-derived SR, SL and velocity can be considered practically useful based on the training requirements of coaches. Parameters derived from video analysis compared to accelerometery were highly correlated (r > 0.91) and therefore consistent regardless of the method of analysis.
Although slight differences were present between the video and accelerometer data, these differences were not practically meaningful.
游泳是一项具有多方面特点的运动，其性能参数细微且往往因游泳者的划水方式而异。提取和分析游泳参数，如单圈时间（LT）、划水长度（SL）、划水频率（SR）和速度，非常耗时。使用经济高效的三轴加速度计可能会简化这一过程，并在一定程度上实现自动化。
确定三轴加速度计在所有四种划水方式中的有效性，并利用基于加速度计的数据研究划水方式的运动学差异。
招募了12名精英游泳运动员参与该研究。该组包括5名男性（年龄：22.2±2.6岁；身高：1.84±0.08米；体重：76.2±3.6千克）和7名女性（年龄：20.7±2.1岁；身高：1.68±0.08厘米；体重：62.0±6.3千克）游泳运动员。
除划水长度和划水次数外，在大多数参数和划水方式中，与视频数据相比，加速度计数据存在微小但显著的偏差（p>0.05）。然而，根据教练的训练要求，基于加速度计得出的SR、SL和速度在实际中可被视为有用。与加速度计相比，视频分析得出的参数高度相关（r>0.91），因此无论分析方法如何，结果都是一致的。
尽管视频数据和加速度计数据之间存在细微差异，但这些差异在实际中并无意义。
