Department of Health and Human Performance, Texas State University, San Marcos, TX 78666, USA.
J Electromyogr Kinesiol. 2012 Dec;22(6):997-1002. doi: 10.1016/j.jelekin.2012.06.002. Epub 2012 Jul 13.
Our purpose was to assess Hoffmann (H) reflex modulations of the soleus and fibularis longus in three body positions (prone, bipedal and unipedal stances) in subjects with and without chronic ankle instability (CAI). Sixteen subjects with unilateral CAI and 15 healthy controls participated. Maximum H-reflexes and motor (M) waves were recorded bilaterally from the soleus and fibularis longus while subjects lied prone and then stood in quiet bipedal and unipedal stances. Maximum H-reflexes were normalized to maximum M waves to obtain H(max):M(max) ratios for the three positions. H-reflex modulations, for each muscle, were quantified as the percent change scores in H(max):M(max) ratios between each pair of positions: prone to bipedal, bipedal to unipedal, and prone to unipedal. There were significant group by limb interactions found for all three modulations (P < 0.05) for the soleus. In the CAI group, soleus modulations in involved limbs were significantly lower than in uninvolved limbs and both limbs in the controls. For the fibularis longus, similar results were found for the bipedal to unipedal and prone to unipedal modulations. Constrained ability of the sensorimotor system to down regulate H-reflex in more demanding postures may represent a potential mechanism of postural control deficits associated with CAI.
我们的目的是评估 Hoffmann (H) 反射在三种体位（俯卧位、双足位和单足位）下对慢性踝关节不稳定（CAI）患者和无 CAI 患者的比目鱼肌和腓骨长肌的调制。16 名单侧 CAI 患者和 15 名健康对照者参与了研究。当受试者处于俯卧位，然后安静地站立在双足位和单足位时，从比目鱼肌和腓骨长肌双侧记录最大 H 反射和运动（M）波。最大 H 反射被归一化为最大 M 波，以获得三个位置的 H(max):M(max) 比值。对于每种肌肉，H 反射调制被量化为 H(max):M(max) 比值在每个位置对之间的百分比变化分数：俯卧位到双足位、双足位到单足位和俯卧位到单足位。对于比目鱼肌，所有三种调制都发现了显著的组-肢相互作用（P < 0.05）。在 CAI 组中，受累肢体的比目鱼肌调制明显低于未受累肢体和对照组的两个肢体。对于腓骨长肌，在双足位到单足位和俯卧位到单足位的调制中也发现了类似的结果。感觉运动系统在更具挑战性的姿势下下调 H 反射的能力受限，可能代表与 CAI 相关的姿势控制缺陷的潜在机制。
