Lumbar Multifidus Muscle Activation Research Articles

Effects of arm and leg positions on lumbar multifidus muscle activity while on hands and knees or while standing

BackgroundThe lumbar multifidus (LMF) muscle, which is involved in the mechanical stability of the lumbar spine, reportedly undergoes atrophy in patients with low back pain. Preventing or mitigating low back pain requires strengthening the LMF muscle; however, methods for triggering selective and significant contraction of this muscle have not been fully studied. This study aims to clarify how, in the hands-and-knees or standing position, the position of the arm and leg on one side affects the activity of the lumbar erector spinae (LES) and LMF muscles.MethodsWe recruited nine adult men with no prior history of low back pain. Measurements were taken in four different postures under varying conditions (that is, one arm and one leg were lifted in either the hands-and-knees or standing position,) as follows: (1) shoulder joint flexion and hip joint extension in the hands-and-knees position; (2) 90° shoulder joint abduction and hip joint abduction in the hands-and-knees position; (3) shoulder joint flexion and hip joint extension in the standing position; and (4) 90° shoulder joint abduction and hip joint abduction in the standing position. The 90° shoulder joint abduction involved simultaneous horizontal abduction, while the hip joint abduction involved simultaneous extension. Muscle activity of the LES and LMF in each posture was measured using a surface electromyograph.ResultsMuscle activity of the LMF was significantly higher in 90° shoulder joint abduction and hip joint abduction than in shoulder joint flexion and hip joint extension in both the hands-and-knees and standing positions. The LES muscle showed no significant differences in activity between each posture.ConclusionsThe results suggest that unilateral 90° shoulder joint abduction and contralateral hip joint abduction in the hands-and-knees and standing positions may produce selective and significant contraction of the LMF muscle.

CORE STABILITY MUSCLE ACTIVITY DURING STANDING LOWER BODY TWISTING EXERCISES.

Little is known about the activity of the abdominal internal oblique (IO) and lumbar multifidus (LM) muscles relative to kinetic chain exercises performed in a standing position. The purpose of this study was to identify the activity of the IO and the LM muscles during weight-bearing exercises. The authors hypothesized that IO and LM muscle activity would vary with lower body positions during the kinetic chain exercises. Nineteen healthy, young, active subjects volunteered to participate. The electromyographic (EMG) activity (via surface EMG) of the abdominal external oblique (EO), IO, and LM muscles on both sides and the rectus femoris and semitendinosus muscles on the dominant side was determined during rhythmical lower body twisting exercise with three lower body positions: straight leg (SL), athletic position (AP), dynamic knee extension (DE) at two exercise speeds: 150 and 90 beats per min. These were reported as % maximum voluntary contraction. Mean EO, IO, and LM muscle activities were also compared with those of common core stability exercises. IO EMG activity was significantly greater in SL than that of AP (p < 0.05). In contrast, LM EMG activity was significantly greater in the DE position than that of both SL and AP positions (p < 0.05). IO muscle activity could be attenuated by the contraction of lower body extensor muscles during the standing position. Basic Laboratory Study, Level 3b.

Using neuromuscular electrical stimulation in conjunction with ultrasound imaging technique to investigate lumbar multifidus muscle activation deficit

Lumbar multifidus muscle (LM) activation deficit has been proposed as a potential underlying mechanism responsible for recurrence episode of low back pain (LBP). The quantification of voluntary LM activation can provide a better understanding of the role of muscle activation deficit in LBP. The objective of this technical report is to propose a new approach using neuromuscular electrical stimulation (NMES) in combination with the ultrasound imaging technique (USI) to investigate the ability of individual to voluntarily activate the LM. We recruited ten participants with a recurrent LBP (rLBP) and twelve participants with no history of LBP (NoLBP). Theoretically, the superimposition of NMES on the LM during maximum voluntary isometric contraction (MVIC) should activate all motor units available in the LM. The percentage of LM activation (%LM) can be calculated by the changes of LM thickness during MVIC, divided by the changes of LM thickness during the combination of MVIC and NMES. This %LM was used to compare between groups. The individuals with rLBP had significantly lower %LM (p < 0.05) compared with the NoLBP counterpart (%LM = 72.4 and 92.9, respectively). Results demonstrate that this new approach can potentially differentiate %LM among individuals with rLBP and NoLBP. This new approach can be potentially used to 1) determine the extent of LM activation deficit, 2) identify the existence of muscle activation deficit in the LM, and 3) objectively measure the effect of the intervention designed to address the LM activation deficit.

Effects of spinal stabilization exercise with real-time ultrasound imaging biofeedback in individuals with chronic nonspecific low back pain: a pilot study.

The use of real-time ultrasound imaging (RUSI) as biofeedback to enhance the performance of spinal stabilization exercise and recovery from low back pain has been a recent trend in musculoskeletal rehabilitation. The aim of this pilot study was to evaluate whether it would be feasible to conduct a randomized controlled trial investigating the effects of spinal stabilization exercise with RUSI biofeedback in individuals with chronic nonspecific low back pain. This was a single-group pretest-posttest quasi-experimental study. Ten consecutive patients with chronic nonspecific low back pain met the study criteria. They received spinal stabilization exercise with the RUSI biofeedback focusing on lumbar multifidus muscle activation. The intervention was provided twice weekly for 6 weeks. Outcome measures were lumbar multifidus muscle cross-sectional area, pain, disability and quality of life assessed at baseline and after intervention. A paired t-test was applied and effect size (Cohen d) was computed. The recruitment and retention rates were 75% and 83% respectively. No adverse events were reported during the study. Compared with the baseline, the participants demonstrated statistically significant improvement in lumbar multifidus muscle cross-sectional area (P<0.05, d=1.03), pain (P<0.001, d=2.56) and disability (P<0.05, d=1.43) with large effect size after the intervention. However, no statistically significant differences were observed for physical and mental health (P>0.05) after the intervention. It was concluded that spinal stabilization exercise with RUSI biofeedback is effective in improving lumbar multifidus muscle cross-sectional area, pain and disability in individuals with chronic nonspecific low back pain. The results demonstrated the feasibility of conducting a future, larger-scale powered randomized controlled trial to confirm these preliminary findings.

Ultrasonography of Lumbar Multifidus Muscle in University American Football Players.

The primary objective of this study was to examine and compare lumbar multifidus (LM) muscle size, asymmetry, and function in university football players with and without low back pain (LBP). A secondary objective was to examine the relationship between LM characteristics and body composition in football players. Ultrasound assessments of the LM muscle were performed in 41 university football players during the preseason. LM muscle cross-sectional area, echo intensity (e.g., indicator of fatty infiltration and connective tissue), thickness at rest, and thickness during submaximal contraction (e.g., contralateral arm lift) measurements in prone and standing positions were obtained bilaterally at the L5-S1 level. Body composition measures were acquired using dual-energy x-ray absorptiometry. A self-administered questionnaire was used to obtain LBP history data. The LM muscle thickness at rest in prone and in standing was significantly smaller in football players who reported the presence of LBP in the previous 3 months. The LM cross-sectional area in prone was significantly and positively correlated with weight, height, lean body mass, total fat mass, and total percent body fat. LM echo intensity was strongly correlated with total percent body fat and total fat mass and negatively correlated with the percent thickness change during contraction. The results of this study provide novel information on LM muscle morphology and activation in football players in prone and standing and suggest that players with LBP in the previous 3 months had smaller LM muscle thickness. LM morphology was strongly correlated with body composition measurements.

Different ways to balance the spine in sitting: Muscle activity in specific postures differs between individuals with and without a history of back pain in sitting

BackgroundPrevious research explored muscle activity in four distinct sitting postures with fine-wire electromyography, and found that lumbar multifidus muscle activity increased incrementally between sitting with flat thoracolumbar and lumbar regions, long thoracolumbar lordosis, or short lordosis confined to the lumbar region. This study used similar methods to explore whether people with a history of low back pain provoked by prolonged sitting used different patterns of trunk muscle activity in specific postures. MethodsFine-wire electromyography electrodes were inserted into the right lumbar multifidus (deep and superficial), iliocostalis (lateral and medial), longissimus thoracis and transversus abdominis muscles. Superficial abdominal muscle activity was recorded with surface or fine-wire electrodes. Electromyography amplitude was compared between postures for the back pain group and observations were contrasted with the changes previously reported for pain-free controls. For comparison between groups normalised and non-normalised electromyography amplitudes were compared. FindingsIndividuals with a history of back pain demonstrated greater activity of the longissimus thoracis muscle in the long lordosis compared with the flat posture [mean difference (95% CI): 46.6 (17.5–75.7)%, normalised to sitting posture peak activity], but pain-free participants did not [mean difference: 7.7 (minus 12–27.6)%]. Pain-free participants modulated lumbar multifidus activity with changes in lumbar curve, but people with a history of pain in prolonged sitting did not change multifidus activity between the long and short lordotic postures. InterpretationIn clinical ergonomic interventions that modify spinal curves and sagittal balance in sitting, the muscle activity used in those postures may differ between people with and without a history of back pain.

Effects of tactile feedback on lumbar multifidus muscle activity in asymptomatic healthy adults and patients with low back pain

BackgroundReduced lumbar multifidus (LM) muscle contraction has been observed in patients with low back pain (LBP). Clinicians often use various strategies to ensure LM activation, including tactile feedback and verbal instruction. However, the effects of tactile feedback on muscle activation have not been studied previously. Therefore, the purpose of this study was to investigate whether or not tactile feedback would increase LM muscle activity in adults with and without LBP. MethodsTwenty asymptomatic adults and 20 patients with existing LBP completed the study. Two electromyographic (EMG) electrodes were applied to both sides of the LM at the L5 segment. EMG activity was collected three times at rest with and without tactile feedback, then five times during contralateral arm lifts with and without tactile feedback. The tactile feedback was applied by direct and continuous hand contact to the bilateral LM over the lumbosacral area. Lastly, two 5-second trials of maximum voluntary isometric contraction (MVIC) during a bilateral arm lift were performed. EMG activity collected at rest and during contralateral arm lifts was normalized to that collected during MVIC. Normalized EMG values of the right side of the asymptomatic group and the painful side of the LBP group were used for data analysis. ResultsStatistical analysis showed significantly decreased LM EMG activity with tactile feedback both at rest and during contralateral arm lifts compared to LM EMG activity without tactile feedback. There was no difference in LM EMG between the asymptomatic and the LBP groups. ConclusionsThe results of the study showed that adding tactile stimulation to verbal instruction appeared to provide an inhibitory effect on LM activity in both asymptomatic healthy adults and patients with LBP. Contrary to common belief, tactical feedback via direct hand contact may reduce LM muscle recruitment, and may lessen the desired treatment effect.

CSM 2015 Orthopaedic Section Platform Presentations (Abstracts OPL1–OPL63)

CSM 2015 Orthopaedic Section Platform Presentations (Abstracts OPL1–OPL63)

Low impact weight-bearing exercise in an upright posture increases the activation of two key local muscles of the lumbo-pelvic region

To date, a range of exercises have been used to improve the function of the lumbar multifidus (LM) and transversus abdominis (TrA) muscles in people with low back pain, but uncertainty remains as to what exactly constitutes meaningful LM and TrA training. We examined the effects of exercising with a new device which combines weight-bearing, an unstable base of support (BOS) (feet), an upright posture with a relatively stable lumbo-pelvic area, and functional lower limb movement, with the aim of exploring which of these elements may be effective, in increasing LM and TrA muscle activity. Twelve non-symptomatic participants had ultrasound images taken of their LM and TrA during a range of conditions, including rest, traditional exercise approaches to LM and TrA recruitment, and exercising on the new device. Our results indicate that an unstable BOS on its own is not enough to increase LM and TrA activity, and that a combination of weight-bearing, an unstable BOS (feet), an upright posture with a relatively stable lumbo-pelvic area, and functional lower limb movement is most effective at increasing LM and TrA activity. This way of exercising appears to recruit LM more effectively than the widely used “swelling” of LM, and to cause automatic TrA and LM recruitment. Importantly, our findings also indicate LM and TrA may have slightly different roles during trunk stabilisation.

Comparison of Abdominal and Lumbar Multifidus Muscle Activity During Unilateral Hip Extension in Prone Position on the Floor and on a Round Foam Roll

The purpose of this study was to compare the muscle activity of the abdominal and lumbar multifidus during unilateral prone hip extension on the floor and on a round foam roll. Fifteen healthy participants were recruited. They were instructed to perform a unilateral hip extension on the floor and on a round foam roll in the prone position. Surface electromyography (EMG) signals were recorded from bilateral lumbar multifidus (LM), external oblique (EO), and internal oblique (IO) muscles. A paired t-test was used to compare muscle activity, with the level of significance set at a=.05. The results showed that bilateral LJVI, EO, IO EMG activity during right-hip extension on a round foam roll was greater than that on the floor, and EMG activity of bilateral LJVI, right EO, and left IO during left-hip extension on a round foam roll was greater than that on the floor (p<.05). These findings suggest that the unilateral hip-extension exercise on a round foam roll can be used to activate the lumbar multifidus and abdominal oblique muscles and causes a different increasing pattern between the two lifting sides.

Experimentally induced pain alters the EMG activity of the lumbar multifidus in asymptomatic subjects

Lumbar musculature plays an important role in stabilization during functional movements such as walking, bending and overhead activities. Current research has focused on the lumbar multifidus (LM) muscle to determine if altered activity of the LM may contribute to low back pain (LBP). Therefore, the purpose of this study was to determine whether experimentally induced LBP affects deep LM muscle activity during functionally oriented tasks, weight shifting and upper extremity lifting. Intramuscular electromyography (EMG) activity of the LM at L4 was measured in 17 healthy adults during a dominant side shoulder flexion and extension task and during a staggered-stance weight shift task. Data were collected at baseline, after pain was induced with hypertonic saline and after the pain had subsided. Comparisons of within-subjects effects were performed with the use of a two-way repeated-measure ANOVA. A significantly higher magnitude of activity was found in the induced pain condition as compared to the baseline condition for the shoulder extension phase of the upper extremity task (p = 0.04). During forward weight shifting, lower values in both the induced pain (p = 0.02) and the recovery conditions (p = 0.01) were measured. During backward weight shifting, lower values were measured during the recovery condition as compared to baseline (p = 0.03). Across trials and subjects the EMG amplitudes were increased during the extension phase of the upper extremity task and decreased during the weight shifting task. These results suggest that the LM does not respond to induced pain in the same manner during different phases of functionally oriented tasks.

Postoperative Rehabilitation Following Lumbar Discectomy With Quantification of Trunk Muscle Morphology and Function: A Case Report and Review of the Literature

A case report and literature review. Optimizing clinical outcomes following lumbar disc surgery is a research priority; however, relatively little attention has been paid to the postoperative management of this population. The transversus abdominis and lumbar multifidus (LM) muscles appear to play a unique role in lumbar spine stability, and may relate to clinical outcome following lumbar disc surgery. The purpose of this case report was to describe the preoperative LM morphology, clinical outcome, and change in transversus abdominis and LM muscle activation in a patient following lumbar disc surgery and motor control exercise initiated in the early postoperative period. A 29-year-old female underwent an 8-week postoperative rehabilitation program emphasizing motor control exercises to restore trunk muscle function 10 days following lumbar disc surgery. The patient experienced clinically important improvements in pain and disability following the postoperative rehabilitation program. Substantial improvements in muscle activation were observed of the transversus abdominis and the LM at the L4-5 level. Minimal change in LM activation and a higher proportion of intramuscular fat was observed at the L5-S1 level. This case report represents limited evidence regarding the feasibility of instituting a rehabilitation program in the early postoperative period following lumbar disc surgery. Improvements in clinical status and muscle function were observed, and a differential change in muscle activation between the L4-5 and L5-S1 levels was noted. The literature regarding rehabilitation following lumbar disc surgery, as well as the neuromuscular changes observed in this population, was reviewed. Additionally, a novel method of examining LM morphology was described and suggestions were made for directions of future research. Therapy, level 4.

Electromyographic Assessment of the Lumbar Multifidus During Motor Control Exercises in Healthy Adults

Motor control exercises are commonly prescribed by healthcare and fitness professionals for the treatment and prevention of low back pain. Unfortunately, evidence quantifying the activation of the deep lumbar multifidus (LM) muscle during exercise is limited. PURPOSE: Therefore, the objective of this study was to determine the level of electromyography (EMG) activity in the deep LM during 7 commonly prescribed motor control exercises. METHODS: Twenty healthy volunteers (31.3 ± 8.9 years; 10 males, 10 females) performed a maximal voluntary isometric contraction (MVIC), followed by 7 motor control exercises in a counterbalanced sequence. Subjects performed 3 trials of each exercise with 60 seconds of rest between trials and a 90 second period of rest between each exercise. Under the guidance of ultrasound imaging, fine-wire electrodes were inserted into the deep LM between the 4th and 5th lumbar levels. The average percent MVIC was used for data analysis. A one-way repeated measure ANOVA and Bonferroni post hoc analysis for pair wise comparisons were calculated. RESULTS: Statistical analysis indicated a significant effect (p < 0.001) across exercises. Post hoc analysis revealed that the prone leg lift (31.95 ± 15.04 %MVIC) resulted in the greatest activation of the LM and was significantly (p < 0.05) different from all other exercises besides the horizontal side support (HSS; 24.57 ± 11.82 %MVIC). The HSS was not statistically different from the next two exercises, prone arm lift (19.35 ± 15.70 %MVIC) and the LM swell (9.35 ± 13.09 %MVIC). The final 3 exercises demonstrated the least amount of LM neuromuscular activation and included the seated trunk rotation (12.32 ± 9.65 %MVIC), side-lying hip draw (9.56 ± 9.13 %MVIC) and quadruped trunk rotation (4.73 ± 3.39 %MVIC). CONCLUSIONS: Kinesiological EMG revealed 3 tiers of LM muscle activation for the examined motor control exercises. Specifically, the prone leg lift and HSS maximally activated the LM. The second tier of exercises involved equal levels of LM activation and included the prone arm lift and LM swell. The final tier consisted of the seated trunk rotation, side-lying hip draw, and the quadruped trunk rotation which demonstrated minimal and variable LM EMG activity. These results help to inform exercise progression clinical decision making for those with LM deficits.

The Relationship of Transversus Abdominis and Lumbar Multifidus Activation and Prognostic Factors for Clinical Success With a Stabilization Exercise Program: A Cross-Sectional Study

Hebert JJ, Koppenhaver SL, Magel JS, Fritz JM. The relationship of transversus abdominis and lumbar multifidus activation and prognostic factors for clinical success with a stabilization exercise program: a cross-sectional study. Objective To examine the relationship between prognostic factors for clinical success with a stabilization exercise program and lumbar multifidus (LM) and transversus abdominis (TrA) muscle activation assessed using rehabilitative ultrasound imaging (RUSI). Design Cross-sectional study. Setting Outpatient physical therapy clinic. Participants Volunteers with current low back pain (N=40). Intervention Not applicable. Main Outcome Measures We examined the relationship between prognostic factors associated with clinical success with a stabilization exercise program (positive prone instability test, age <40y, aberrant movements, straight leg raise >91°, presence of lumbar hypermobility) and degree of TrA and LM muscle activation assessed by RUSI. Results Significant univariate relationships were identified between LM muscle activation and the number of prognostic factors present (Pearson correlation coefficient [ r] =−.558, P=.001), as well as the individual factors of a positive prone instability test (point biserial correlation coefficient [ r pbis ]=.376, P=.018) and segmental hypermobility ( r pbis =.358, P=.025). The multivariate analyses indicated that after controlling for other variables, the addition of the variable “number of prognostic factors present” resulted in a significant increase in R 2 ( P=.006). No significant univariate or multivariate relationships were observed between the prognostic factors and TrA muscle activation. Conclusions Decreased LM muscle activation, but not TrA muscle activation, is associated with the presence of factors predictive of clinical success with a stabilization exercise program. Our findings provide researchers and clinicians with evidence regarding the construct validity of the prognostic factors examined in this study, as well as the potential clinical importance of the LM muscle as a target for stabilization exercises.