Postural Stability Related To Proprioception More Than Strength Among People With Anterior Cruciate Ligament Reconstruction

PURPOSE: The relationships between dynamic postural stability and different physical functions are important to develop precise rehabilitation approaches among people with anterior cruciate ligament reconstruction (ACLR). This study investigated correlations of strength, proprioception, and tactile sensation to postural stability among people with ACLR. METHODS: Forty-four people over six months post ACLR (age: 27.9 ± 6.8 years old, height: 181.7 ± 8.7 cm, body mass: 80.6 ± 9.4 kg, postoperative duration: 10.3 ± 3.6 months) were recruited from a local hospital. Dynamic postural stability was tested and represented by the time to stabilization (TTS) of ground reaction force in the anterior-posterior (AP) and mediolateral (ML) directions during jump landing (KISTLER, 9287BA, Switzerland). The muscle strength and proprioception thresholds of knee flexion/extension were assessed using a strength testing system (IsoMed 2000, Hemau, Germany) and a proprioception testing device (Sunny, AP-II, China), respectively. The tactile sensation of the great toe, 1st and 5th metatarsal, arch, and the heel was measured with the Semmes–Weinstein monofilaments (North Coast Medical, Inc., Morgan Hill, CA, USA). Exploratory factor analysis and Multivariable linear regression were used to explore the relationships. RESULTS: Factor analysis indicated that Factor 1 (F1), factor 2 (F2), and factor 3 (F3) were the summaries of tactile sensation, strength, and proprioception, respectively, with a Kaiser Meyer Olkin value of 0.718 and sphericity<0.001. Regressions analysis resulted the following equations: TTSAP = 843.30 - 114.30 × F2; TTSML = 554.07 - 94.63 × F2 + 159.45 × F3. In the first equation, adjusted r2 = 0.249, pF2 = 0.001, and βF2 = -0.457; in the second equation, adjusted r2 = 0.393, pF2 = 0.012, pF3 < 0.001, βF2 = -0.314, and βF3 = 0.529. CONCLUSION: Proprioception had a greater level of correlation with postural stability than strength. Proprioception should have priority in ACLR rehabilitation, followed by strength. Funding was provided by Shandong Province Young Innovative Talent Introduction and Cultivation Program (2019-183).