Palmer Ty B, Akehi Kazuma, Thiele Ryan M, Smith Douglas B, Warren Aric J, Thompson Brennan J
School of Health Sciences, Kent State University, OH;
J Athl Train. 2015 May;50(5):467-74. doi: 10.4085/1062-6050-49.6.04. Epub 2015 Feb 6.
Passive straight-legged-raise (SLR) assessments have been performed with the ankle fixed in dorsiflexion (DF), plantar-flexion (PF), or neutral (NTRL) position. However, it is unclear whether ankle position contributes to differences in the passive resistance measured during an SLR assessment.
To examine the influence of ankle position during an SLR on the passive torque, range of motion (ROM), and hamstrings electromyographic (EMG) responses to passive stretch of the posterior hip and thigh muscles.
Crossover study.
Research laboratory.
A total of 13 healthy volunteers (5 men: age = 24 ± 3 years, height = 178 ± 6 cm, mass = 85 ± 10 kg; 8 women: age = 21 ± 1 years, height = 163 ± 8 cm, mass = 60 ± 6 kg).
INTERVENTION(S): Participants performed 6 randomly ordered passive SLR assessments involving 2 assessments at each condition, which included the ankle positioned in DF, PF, and NTRL. All SLRs were performed using an isokinetic dynamometer programmed in passive mode to move the limb toward the head at 5°/s.
MAIN OUTCOME MEASURE(S): During each SLR, maximal ROM was determined as the point of discomfort but not pain, as indicated by the participant. Passive torque and EMG amplitude were determined at 4 common joint angles (θ) separated by 5° during the final common 15° of ROM for each participant.
Passive torque was greater for the DF condition than the NTRL (P = .008) and PF (P = .03) conditions at θ3 and greater for the DF than NTRL condition (P = .02) at θ4. Maximal ROM was lower for the DF condition than the NTRL (P = .003) and PF (P < .001) conditions. However, we found no differences among conditions for EMG amplitude (P = .86).
These findings suggest that performing SLRs with the ankle positioned in DF may elicit greater passive torque and lower ROM than SLRs with the ankle positioned in PF or NTRL. The greater passive torque and lower ROM induced by the DF condition possibly were due to increased tension in the neural structures of the proximal thigh.
被动直腿抬高（SLR）评估是在踝关节固定于背屈（DF）、跖屈（PF）或中立（NTRL）位时进行的。然而，尚不清楚踝关节位置是否会导致SLR评估期间测得的被动阻力存在差异。
研究SLR过程中踝关节位置对被动扭矩、运动范围（ROM）以及后髋和大腿肌肉被动拉伸时腘绳肌肌电图（EMG）反应的影响。
交叉研究。
研究实验室。
共13名健康志愿者（5名男性：年龄=24±3岁，身高=178±6厘米，体重=85±10千克；8名女性：年龄=21±1岁，身高=163±8厘米，体重=60±6千克）。
参与者进行6次随机排序的被动SLR评估，每种情况进行2次评估，包括踝关节处于DF、PF和NTRL位。所有SLR均使用等速测力计以被动模式编程，使肢体以5°/秒的速度向头部移动。
在每次SLR过程中，最大ROM被确定为参与者表示不适但无疼痛的点。在每个参与者ROM的最后共同15°期间，在4个相隔5°的常见关节角度（θ）处确定被动扭矩和EMG幅度。
在θ3时，DF位的被动扭矩大于NTRL位（P = 0.008）和PF位（P = 0.03），在θ4时，DF位的被动扭矩大于NTRL位（P = 0.02）。DF位的最大ROM低于NTRL位（P = 0.003）和PF位（P < 0.001）。然而，我们发现各情况之间的EMG幅度无差异（P = 0.86）。
这些发现表明，与踝关节处于PF或NTRL位的SLR相比，踝关节处于DF位进行SLR可能会产生更大的被动扭矩和更低的ROM。DF位引起的更大被动扭矩和更低ROM可能是由于大腿近端神经结构张力增加所致。
