Faculty of Health, Sport and Human Performance, Adams Centre for High Performance, University of Waikato, Mount Maunganui, Tauranga, New Zealand.
J Athl Train. 2017 Oct;52(10):910-917. doi: 10.4085/1062-6050-52.8.02. Epub 2017 Sep 22.
The Lower Quarter Y-Balance Test (LQ-YBT) was developed to provide an effective and efficient screen for injury risk in sports. Earlier protocol recommendations for the LQ-YBT involved the athlete placing the hands on the hips and the clinician normalizing scores to lower limb length measured from the anterior-superior iliac spine to the lateral malleolus. The updated LQ-YBT protocol recommends the athlete's hands be free moving and the clinician measure lower limb length to the medial malleolus.
To investigate the effect of hand position and lower limb length measurement method on LQ-YBT scores and their interpretation.
Cross-sectional study.
National Sports Institute of Malaysia.
A total of 46 volunteers, consisting of 23 men (age = 25.7 ± 4.6 years, height = 1.70 ± 0.05 m, mass = 69.3 ± 9.2 kg) and 23 women (age = 23.5 ± 2.5 years, height = 1.59 ± 0.07 m, mass = 55.7 ± 10.6 kg).
INTERVENTION(S): Participants performed the LQ-YBT with hands on hips and hands free to move on both lower limbs.
MAIN OUTCOME MEASURE(S): In a single-legged stance, participants reached with the contralateral limb in each of the anterior, posteromedial, and posterolateral directions 3 times. Maximal reach distances in each direction were normalized to lower limb length measured from the anterior-superior iliac spine to the lateral and medial malleoli. Composite scores (average of the 3 normalized reach distances) and anterior-reach differences (in raw units) were extracted and used to identify participants at risk for injury (ie, anterior-reach difference ≥4 cm or composite score ≤94%). Data were analyzed using paired t tests, Fisher exact tests, and magnitude-based inferences (effect size [ES], ±90% confidence limits [CLs]).
Differences between hand positions in normalized anterior-reach distances were trivial (t = -2.075, P = .041; ES = 0.12, 90% CL = ±0.10). In contrast, reach distances were greater when the hands moved freely for the normalized posteromedial (t = -6.404, P < .001; ES = 0.42, 90% CL = ±0.11), posterolateral (t = -6.052, P < .001; ES = 0.58, 90% CL = ±0.16), and composite (t = -7.296, P < .001; ES = 0.47, 90% CL = ±0.11) scores. A similar proportion of the cohort was classified as at risk with the hands on the hips (35% [n = 16]) and the hands free to move (43% [n = 20]; P = .52). However, the participants classified as at risk with the hands on the hips were not all categorized as at risk with the hands free to move and vice versa. The lower limb length measurement method exerted trivial effects on LQ-YBT outcomes.
Hand position exerted nontrivial effects on LQ-YBT outcomes and interpretation, whereas the lower limb length measurement method had trivial effects.
下四分之一 Y 平衡测试（LQ-YBT）旨在为运动损伤风险提供一种有效和高效的筛查方法。早期的 LQ-YBT 协议建议运动员将手放在臀部，临床医生将分数归一化为从髂前上棘到外踝的下肢长度。更新的 LQ-YBT 协议建议运动员的手可以自由移动，临床医生测量下肢长度到内踝。
探讨手的位置和下肢长度测量方法对 LQ-YBT 评分及其解释的影响。
横断面研究。
马来西亚国家体育研究所。
共有 46 名志愿者，包括 23 名男性（年龄=25.7±4.6 岁，身高=1.70±0.05m，体重=69.3±9.2kg）和 23 名女性（年龄=23.5±2.5 岁，身高=1.59±0.07m，体重=55.7±10.6kg）。
参与者在双腿单腿站立时用手放在臀部和自由移动双手进行 LQ-YBT。
在单侧肢体站立时，参与者用对侧肢体在前后、后内侧和后外侧方向各伸展 3 次。每个方向的最大伸展距离被归一化为从髂前上棘到外踝和内踝的下肢长度。提取和使用综合评分（3 个归一化伸展距离的平均值）和前伸差异（原始单位）来识别有受伤风险的参与者（即前伸差异≥4cm 或综合评分≤94%）。使用配对 t 检验、Fisher 确切检验和基于幅度的推断（效应大小[ES]，±90%置信区间[CL]）分析数据。
手位置在手的位置在正常化前伸距离方面存在微小差异（t=-2.075，P=0.041；ES=0.12，90%CL=±0.10）。相比之下，当手自由移动时，后内侧（t=-6.404，P<0.001；ES=0.42，90%CL=±0.11）、后外侧（t=-6.052，P<0.001；ES=0.58，90%CL=±0.16）和综合（t=-7.296，P<0.001；ES=0.47，90%CL=±0.11）评分的伸展距离更大。有相似比例的队列被归类为有受伤风险（手放在臀部：35%[n=16]；手自由移动：43%[n=20]；P=0.52）。然而，被归类为有受伤风险的手放在臀部的参与者并不都被归类为有受伤风险的手自由移动，反之亦然。下肢长度测量方法对 LQ-YBT 结果有轻微影响。
手的位置对 LQ-YBT 结果和解释有重要影响，而下肢长度测量方法有轻微影响。
