Effects of Lumbosacral Manipulation on Isokinetic Strength of the Knee Extensors and Flexors in Healthy Subjects: A Randomized, Controlled, Single-Blind Crossover Trial

Abstract

Objective: The purpose of this study was to investigate the effect of manual manipulations targeting the lumbar spine and/or sacroiliac joint on concentric knee extension and flexion forces. Torque production was measured during isometric and isokinetic contractions. Methods: This was a randomized, controlled, single-blind crossover design with 21 asymptomatic, college-aged subjects who had never received spinal manipulation. During 2 separate sessions, subjects' peak torques were recorded while performing maximal voluntary contractions on an isokinetic dynamometer. Isometric knee extension and flexion were recorded at 60°of knee flexion, in addition to isokinetic measurements obtained at 60°/s and 180°/s. Baseline measurements were acquired before either treatment form of lumbosacral Journal of Chiropractic Medicine (2015) 14, 240-248 manipulation or sham manipulation, followed by identical peak torque measurements within 5 and 20 minutes posttreatment. Data were analyzed with a repeated measures analysis of variance. Results: A statistically significant difference did not occur between the effects of lumbosacral manipulation or the sham manipulation in the percentage changes of knee extension and flexion peak torques at 5 and 20 minutes posttreatment. Similar, nonsignificant results were observed in the overall percentage changes of isometric contractions (spinal manipulation 4.0 ± 9.5 vs sham 1.2 ± 6.3, P = .067), isokinetic contractions at 60°/s (spinal manipulation − 4.0 ± 14.2 vs sham − 0.3 ± 8.2, P = .34), and isokinetic contractions at 180°/s (spinal manipulation − 1.4 ± 13.9 vs sham − 5.5 ± 20.0, P = .18). Conclusion:The results of the current study suggest that spinal manipulation does not yield an immediate strength-enhancing effect about the knee in healthy, college-aged subjects when measured with isokinetic dynamometry.

The effects of spinal manipulation on performance-related outcomes in healthy asymptomatic adult population: a systematic review of best evidence

“…We included 20 articles with a low risk of bias, of which seven were randomized controlled crossover studies [30, 31, 35, 41–43, 46], 10 were randomized controlled trials (RCT) [13, 14, 32–34, 37–39, 44, 47] and three were RCT pilot studies [36, 40, 45].…”

“…Four studies reported on adverse events [30, 36, 40, 44]. Four studies reported on physiological outcomes [30, 33, 42, 47], 16 studies reported on biomechanical outcomes [13, 14, 31, 34–46], three of which also reported on sport-specific outcomes [40, 42, 45], and one additional study reported on performance variables for specific sports [32, 42].…”

“…Seven studies examined the effect of SMT on muscle activation or strength of the lower limb in healthy subjects [13, 31, 35, 36, 38, 40, 46] (Table 1). Four of these studies identified a significant change in muscle function [31, 35, 36, 38].…”

“…We did not calculate mean change and 95% CI from this study. In contrast, two studies reported no significant effect of SMT; one showed no significant change in quadriceps MVC after L3–4 SMT compared to sham manipulation [13] and the second showed no significant change in knee extension or flexion muscle activation or peak torques at 60°/sec and 180°/sec during isokinetic concentric testing compared to a non-specific drop piece procedure [46].…”

“…n = 15Sham: Simulated SMT to the left side of the L3/4 motion segment while in the lumbar roll position. n = 15Immediate after SMTAverage of the force of two maximal isometric contractions of the quadriceps femoris (N).Between group difference SMT-Control:5.1 N (− 3.67, 13.87) Sanders et al, 2015 [46]Healthy, asymptomatic, never received SMT; 20–35 years; Kentucky, USA; n = 21; Randomized, controlled, single-blind crossover design.Bilateral side-lying lumbar and/or SIJ SMT to identified restrictions. n = 21Sham: use of drop piece and non-specific thrust through lumbar paraspinals.…”