Centre for Sport and Exercise Sciences, University of Malaya, Kuala Lumpur 50603, Malaysia.
Centre for Sport and Exercise Sciences, University of Malaya, Kuala Lumpur 50603, Malaysia.
Hum Mov Sci. 2020 Jun;71:102629. doi: 10.1016/j.humov.2020.102629. Epub 2020 May 16.
Familiarization is necessary for an accurate strength assessment as it reduces confounding factors such as learning and training effects. However, the number of contractions required for familiarization and whether cross-limb transfer during familiarization could affect bilateral assessment are unknown. This study aimed at identifying the number of maximum contractions required for isokinetic knee extension and flexion familiarization in both dominant (D) and non-dominant limb (ND).
Twenty-eight right-limb dominant males (age: 22.64 ± 2.60 years, BMI: 23.82 ± 2.85 kg/m) performed a total of 6 sets (each consisted of 5 continuous maximum contractions) at 60/s for each limb.
The number of sets required for familiarization is determined when the average peak torque achieved stabilization from the series of contractions of each limb. For knee extension, 3 sets (15 contractions) were required for familiarization, whereas 2 sets (10 contractions) for knee flexion in both limbs. Interestingly, for knee extension in ND, the number of sets required for familiarization was reduced to 2 following contralateral contractions in D, however, for knee extension in D, there was no difference in the number of sets required for familiarization following contralateral contractions in ND. While for knee flexion, no cross-limb transfer was observed. These observations suggest the presence of cross-limb transfer from D to ND during familiarization which implies the involvement of the central nervous system.
Practically, familiarization for bilateral isokinetic strength assessment for knee extension and flexion at 60/s should begin with the dominant limb for 3 sets to obtain accurate and reliable measurements.
由于熟悉过程可以减少学习和训练效应等混杂因素，因此进行准确的力量评估前需要进行熟悉过程。但是，熟悉过程所需的收缩次数以及熟悉过程中是否会发生交叉肢体转移是否会影响双侧评估尚不清楚。本研究旨在确定在主导（D）和非主导（ND）肢体上进行等速膝关节屈伸熟悉过程所需的最大收缩次数。
28 名右利手男性（年龄：22.64±2.60 岁，BMI：23.82±2.85kg/m）在 60/s 的速度下，每条腿总共进行 6 组（每组由 5 个连续的最大收缩组成）。
当每条肢体的收缩系列中获得的平均峰值扭矩稳定时，就可以确定进行熟悉所需的组数。对于膝关节伸展，需要进行 3 组（15 次收缩）熟悉，而对于双侧膝关节伸展和屈曲，只需进行 2 组（10 次收缩）熟悉。有趣的是，对于 ND 侧的膝关节伸展，在 D 侧进行对侧收缩后，熟悉所需的组数减少到 2 组，但对于 D 侧的膝关节伸展，在 ND 侧进行对侧收缩后，熟悉所需的组数没有差异。而对于膝关节屈曲，没有观察到交叉肢体转移。这些观察结果表明，在熟悉过程中，从 D 侧到 ND 侧存在交叉肢体转移，这意味着中枢神经系统的参与。
实际上，在 60/s 进行双侧等速力量评估时，应从主导侧开始进行 3 组熟悉，以获得准确可靠的测量结果。
