Predicting a beneficial response to motor control training in patients with low back pain: a longitudinal cohort study.

PURPOSE: Exercise therapy such as motor control training (MCT) has been shown to reduce pain and disability in people with low back pain (LBP). It is unknown which patients are most likely to benefit. This longitudinal cohort study aimed to: (1) retrospectively examine records from a large cohort of patients who received MCT treatment, (2) identify potentially important predictors of response to MCT and (3) test the predictors on an independent (split) sample derived from the original cohort of patients, using one group to identify the predictors and the other to test them. METHODS: The response of 775 patients with LBP to MCT was classified as 'improved' or 'not improved' based on self-reported change in pain levels and symptoms. Measures were examined for associations with improvement and entered into a logistic regression model to classify patients as low, medium or high benefits of improvement with MCT. The model was tested on an independent sample. RESULTS: A positive response was seen in patients with: no evidence of scoliosis [OR = 4.0, 95% CI (1.7, 9.6)], LBP without associated groin pain [OR = 2.2, 95% CI (1.0, 5.0)], LBP which was chronic recurrent in nature [OR = 3.1, 95% CI (1.8, 5.3)] and poor results on muscle testing of the multifidus muscle [OR = 2.0, 95% CI (1.1, 3.7)]. Testing on an independent sample confirmed that patients could be classified into benefit groups. CONCLUSIONS: This study provides a first step towards assisting clinicians to select patients most likely to respond to MCT. These slides can be retrieved under Electronic Supplementary Material.

Small Multifidus Muscle Size Predicts Football Injuries.

BACKGROUND: In Australian football, lower limb injuries have had the highest incidence and prevalence rates. Previous studies have shown that football players with relatively more severe preseason and playing season hip, groin, and thigh injuries had a significantly smaller multifidus muscle compared with players with no lower limb injuries. Rehabilitation of the multifidus muscle, with restoration of its size and function, has been associated with decreased recurrence rates of episodic low back pain and decreased numbers of lower limb injuries in football players. Assessment of multifidus muscle size and function could potentially be incorporated into a model that could be used to predict injuries in football players. PURPOSE: To examine the robustness of multifidus muscle measurements as a predictor of lower limb injuries incurred by professional football players. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Ultrasound examinations were carried out on 259 male elite football players at the start of the preseason and 261 players at the start of the playing season. Injury data were obtained from records collected by the Australian Football League (AFL) club staff during the preseason and the playing season. RESULTS: Decreased size of the multifidus muscle at L5 consistently predicted injury in the preseason and playing season. Asymmetry of the multifidus muscle and low back pain were significantly related to lower limb injuries in the preseason, and having no preferred kicking leg was related to season injuries. Seasonal change in the size of the multifidus muscle indicating a decrease in muscle mass was linked to injury. Sensitivity and specificity of the model were 60.6% and 84.9% for the preseason and 91.8% and 45.8% for the playing season, respectively. CONCLUSION: A model was developed for prediction of lower limb injuries in football players with potential utility for club medical staff. Of particular note is the finding that changes in muscle size from the preseason to the playing season predicted injury. CLINICAL RELEVANCE: As size of the multifidus muscle has been shown to be modifiable with training and has been associated with reduced pain and occurrence of injuries, this information could be incorporated in current programs of injury prevention.

Effect of motor control training on muscle size and football games missed from injury.

PURPOSE: This panel-randomized intervention trial was designed to examine the effect of a motor control training program for elite Australian Football League players with and without low back pain (LBP). METHODS: The outcome measures included cross-sectional area (CSA) and symmetry of multifidus, quadratus lumborum, and psoas muscles and the change in CSA of the trunk in response to an abdominal drawing-in task. These measures of muscle size and function were performed using magnetic resonance imaging. Availability of players for competition games was used to assess the effect of the intervention on the occurrence of injuries. The motor control program involved performance of voluntary contractions of the multifidus and transversus abdominis muscles while receiving feedback from ultrasound imaging. Because all players were to receive the intervention, the trial was delivered as a stepped-wedge design with three treatment arms (a 15-wk intervention, a 8-wk intervention, and a waitlist control who received a 7-wk intervention toward the end of the playing season). Players participated in a Pilates program when they were not receiving the intervention. RESULTS: The intervention program was associated with an increase in multifidus muscle size relative to results in the control group. The program was also associated with an improved ability to draw-in the abdominal wall. Intervention was commensurate with an increase in availability for games and a high level of perceived benefit. CONCLUSIONS: The motor control program delivered to elite footballers was effective, with demonstrated changes in the size and control of the targeted muscles. In this study, footballers who received the intervention early in the season missed fewer games because of injury than those who received it late in the playing season.

The relationship of transversus abdominis and lumbar multifidus clinical muscle tests in patients with chronic low back pain.

INTRODUCTION: Previous research of transversus abdominis (TrA) and multifidus muscle function in the presence of chronic low back pain (LBP) has investigated these muscles in isolation. In clinical practice, it is assumed that a relationship exists between these muscles and so they are often assessed and rehabilitated together. However, no studies have tested or documented this association. This study aimed to examine the relationships between clinical muscle testing and other measures taken in the course of a clinical assessment at a back clinic. METHODS: This retrospective chart audit examined the files of 82 patients (40 Males, 42 Females) for results of clinical tests of TrA and multifidus muscle contraction, multifidus muscle size measurements and other clinical measures such as distribution of pain and pain on manual examination. RESULTS: The ability to contract multifidus was related to the ability to contract TrA with the odds of a good contraction of multifidus being 4.5 times higher for patients who had a good contraction of TrA. A poor ability to contract multifidus was related to poor TrA contraction. Patients with unilateral LBP had more multifidus muscle asymmetry (11.6%) than those with bilateral/central pain (0.01%) and had a poor multifidus contraction on the affected side (p < 0.01). No other significant relationships were found. DISCUSSION & CONCLUSION: Current clinical practice of assessment and rehabilitation of both TrA and multifidus muscles in patients with chronic LBP is supported by the findings of this study. Future studies may investigate if a neurophysiological relationship exists between these muscles.