College of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan.
The Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, Kentucky.
Sports Health. 2024 Jan-Feb;16(1):19-25. doi: 10.1177/19417381221147304. Epub 2023 Jan 23.
Altered reorganization of the sensorimotor system after an initial lateral ankle sprain may lead to a chronic neuromuscular maladaptation in multiple body locations. Specifically, decreased diaphragm contractility has been observed in patients with chronic ankle instability (CAI). The diaphragm has an essential role in postural control. Decreased diaphragm contractility could associate with diminished postural control commonly observed in patients with CAI. However, no study has determined if diaphragm contractility contributes to postural control in a CAI population.
Decreased diaphragm contractility would be negatively associated with static postural control in patients with CAI.
Cross-sectional study design.
Level 4.
A total of 15 participants with CAI participated voluntarily. An ultrasonography assessment was performed to quantify the right and left hemidiaphragm thickness at the end of resting inspiration and expiration in supine while breathing quietly. The degree of diaphragm contractility was calculated from the diaphragm thickness. Participants performed 3 eyes-open trials of a 20-second single-leg balance task on the involved limb. Static postural control measures included the center of pressure velocity (COPV) and mean of time-to-boundary (TTB) minima in the anteroposterior (AP) and mediolateral directions.
Moderate correlations of the right hemidiaphragm contractility were observed with COPV (ρ = -0.54) and TTB mean minima (ρ = 0.56) ( < 0.05) in the AP direction. The left hemidiaphragm contractility was moderately correlated with COPV (ρ = -0.56) and TTB mean minima (ρ = 0.60) ( < 0.05) in the AP direction.
Lower diaphragm contractility may be associated with diminished static postural control in the AP direction in patients with CAI.
This study highlights diaphragm contractility could be a potential connection with diminished static postural control in patients with CAI. Our data raise new avenues for future exploration including potential beneficial effects of implementation of diaphragm breathing exercises and techniques for restoring static postural control in patients with CAI.
初次踝关节外侧扭伤后，感觉运动系统的重组可能会导致多个身体部位的慢性神经肌肉适应不良。具体来说，慢性踝关节不稳定（CAI）患者的膈肌收缩力降低。膈肌在姿势控制中起着重要作用。膈肌收缩力降低可能与 CAI 患者常见的姿势控制能力下降有关。然而，尚无研究确定膈肌收缩力是否会影响 CAI 人群的姿势控制。
CAI 患者的膈肌收缩力降低与静态姿势控制呈负相关。
横断面研究设计。
4 级。
共有 15 名 CAI 患者自愿参与。在仰卧位安静呼吸时，通过超声检查评估右和左半膈肌在静息吸气末和呼气末的厚度。从膈肌厚度计算膈肌收缩力程度。参与者在受累肢体上进行 3 次睁眼 20 秒单腿平衡任务试验。静态姿势控制测量包括前/后（AP）和中/侧（ML）方向的中心压力速度（COPV）和最小时间到边界（TTB）均值。
右侧膈肌收缩力与 COPV （ρ=-0.54）和 TTB 均值最小值（ρ=-0.56）（<0.05）呈中度相关。左侧膈肌收缩力与 COPV（ρ=-0.56）和 TTB 均值最小值（ρ=0.60）（<0.05）呈中度相关。
CAI 患者的膈肌收缩力降低可能与 AP 方向的静态姿势控制能力下降有关。
本研究强调膈肌收缩力可能与 CAI 患者静态姿势控制能力下降有关。我们的数据为未来的探索提供了新的途径，包括膈肌呼吸练习和恢复 CAI 患者静态姿势控制的技术的潜在有益效果。
