Ipsilateral Erector Spinae Research Articles

Effect of Box Height on the Muscle Activity during the Bulgarian Split Squat Exercise

The purpose of this study was to compare the effects of box height on muscle activity of the ipsilateral erector spinae and gluteus maximus of the dominant leg during the Bulgarian split squat (BSS) exercise. A total of 21 healthy male participants were selected for this study. The participants repeated the Bulgarian split squat three times each on boxes of tibia height and half-tibia height. Surface EMG activity was recorded in the erector spinae and gluteus maximus for five seconds as the knees touched the mat and ascended during the Bulgarian split squat. Maximal voluntary isometric contraction (MVIC) calculated through the manual muscle test was used to normalize EMG activity. A paired sample t-test was conducted to evaluate the changes in the muscle activity of the erector spinae and gluteus maximus between box heights, and a p-value less than 0.05 was considered statistically significant. Although the EMG activity levels of the erector spinae and gluteus maximus were higher during BSS on a box of tibia height, the differences in muscle activity were not statistically significant (p>0.05). The muscle activity levels of the erector spinae and gluteus maximus were lower and similar, respectively, during Bulgarian split squat on a box of half-tibia height compared with a box of tibia height. Thus, it is recommended that BSS be conducted on boxes with shorter heights.

Activity of Posterior Oblique Sling Muscles during Quadruped Hip Extension with Different Shoulder Positions

While various studies have been conducted on trunk muscle activation in the quadruped position, no research has been conducted on posterior oblique sling (POS) muscle activation in the quadruped position despite its clinical importance. It has been demonstrated that the movement of the upper extremity affects the muscle activity of the contralateral lower extremity through the POS. The purpose of this study was to compare the EMG of the POS muscles during quadruped hip extension (QHE) with different shoulder positions. The participants performed hip extension in the quadruped position without shoulder movement (quadruped hip extension; QHE), QHE with shoulder extension and internal rotation (QHE with SEI), and QHE with shoulder flexion and external rotation (QHE with SFE). EMG of the POS muscles was measured during three different positions. During the QHE with SFE position, the lower trapezius has the highest EMG among all the POS muscles. Additionally, the contralateral erector spinae, ipsilateral erector spinae, and gluteus maximus presented higher EMG activity during QHE with SFE than during QHE and QHE with SEI. Therefore, QHE with SFE position may be clinically recommended as an effective exercise to improve EMG activity of POS muscles and increase lumbopelvic stability.

Motor recruitment pattern during the prone hip extension test: is hip extension initiated by the hip or the lumbar extensor muscles?

Background/Aims Prone hip extension motion pattern derives from the motor muscle firing pattern, and functional deficits are determined by comparing this pattern with a normal prone hip extension motion muscle recruitment pattern, defined more than 30 years ago by scientifically insufficient methods. The aim of this study was to examine the differences between electromyography recruitment onsets and orders of muscles participating in prone hip extension motion, and to determine whether there is a consistent and dominant motor pattern. Methods The sample consisted of 106 healthy participants. Onset times of semitendinosus, ipsilateral and contralateral erector spinae muscles were determined as 10% of the peak rectified amplitude of the electromyography signal for each of the 18 prone hip extension bilateral repetitions. These values were used to determine the recruitment order for each repetition, as well as to calculate the average ipsilateral and contralatral normalised onset times (ie relative times to firing of the semitendinosus muscle). The main analysis was performed using a one-way analysis of variance. The level of statistical significance was set at P<0.05. Results One-way analysis of variance revealed a significantly delayed onset of prone hip extension of the contralateral erector spinae muscles compared to the other muscles (F=7.02; P<0.001; Cohen's f=0.209). Muscle activation initiated by the semitendinosus and ipsilateral erector spinae muscles was the most common. Conclusions The ipsilateral erector spinae muscle contracts simultaneously with the semitendinosus muscle as a proximal stabiliser, enabling distal hip mobility. The use of the prone hip extension test in recognising dysfunction is limited to when the contralateral erector spinae muscle is initiated first during prone hip extension.

New Strategies for Controlling Pelvic Transverse Rotation and Selective Activation of Hip Muscles during Prone Hip Extension with Knee Flexion

Background : Prone hip extension with knee flexion (PHEKF) is a commonly used exercise for strengthening the gluteal muscles. However, PHEKF exercise is associated with a risk of increased hamstring and erector spinae activities, lumbar rotation to compensate for gluteal muscle weakness. Therefore, PHEKEF with isometric hip 30 abduction was evaluated in this study using Thera-Band to reduce pelvic transverse rotation compensation and effectively strengthen gluteal muscle strength. Objectives : The purpose of this study was to investigate the activity of the gluteus maximus (GMax), gluteus medius (GMed), erector spinae (ES) and hamstring (HAM) muscles and pelvic transverse rotation during PHEKF in three conditions. Methods : Fifteen healthy women participated in the study. The pelvic transverse rotation was measured using a smart phone-based measurement tool. The surface electromyography was attached the GMax, GMed, ES and HAM muscles. Then, the maximum voluntary isometric contraction was measured. The PHEKF exercise was performed in three different conditions (PHEKF, PHEKF with 30º hip abduction, and PHEKF with 30º isometric hip abduction [IHA]) by randomly. A one-way repeated measures ANOVA was performed to determine the difference in pelvic transverse rotation angle and muscle activity between the condition. Results : The GMax and GMed amplitudes were highest in PHEKF with 30° IHA, followed by 30º and 0° hip abduction during PHEKF (GMax, p < 0.001; GMed, p < 0.001). HAM and ipsilateral ES amplitudes were not significantly different among the three conditions (ipsilateral ES, p = 0.268; HAM, p = 0.577). In the pelvic transverse rotation angle and contralateral ES, the PHEKF with 30° IHA showed significantly lower than PHEKE with 30° abduction (the pelvic transverse rotation angle, p < 0.05; contralateral ES, p < 0.05). Conclusions : The results of these studies can examine that the PHEK with 30º IHA was effective to control pelvic transverse rotation and increase the contribution of the selective muscles activities of GMax and GMed muscles.

Trunk muscle activation patterns during active hip abduction test during remission from recurrent low back pain: an observational study

BackgroundThe active hip abduction test (AHAbd) is widely used to evaluate lumbopelvic stability, but the onset of trunk muscle activation during the test in individuals with recurrent low back pain (rLBP) has not been investigated so far. It is important to investigate the pattern of trunk muscle activation during the AHAbd test to provide insight into the interpretation of observation-based assessment results; this may help to create exercise therapy interventions, from a movement control perspective, for people seeking treatment for rLBP. The purpose of this study was to compare the timing of trunk muscle activation between individuals with and without rLBP and to assess potential differences.Methods Seventeen subjects in remission from rLBP and 17 subjects without rLBP were recruited. We performed surface electromyography of the transversus abdominis/internal abdominal oblique, external oblique, erector spinae, and gluteus medius muscles during the AHAbd test on both sides. The onset of trunk muscle activation was calculated relative to the prime mover gluteus medius. The independent-samples t- and Mann-Whitney U tests were used to compare the onset of trunk muscle activation between the two groups.ResultsThe onset of transversus abdominis/internal abdominal oblique activation on the ipsilateral (right AHAbd: −3.0 ± 16.2 vs. 36.3 ± 20.0 msec, left AHAbd: −7.2 ± 18.6 vs. 29.6 ± 44.3 ms) and contralateral sides (right AHAbd: −11.5 ± 13.9 vs. 24.4 ± 32.3 ms, left AHAbd: −10.1 ± 12.5 vs. 23.3 ± 17.2 ms) and erector spinae on the contralateral side (right AHAbd: 76.1 ± 84.9 vs. 183.9 ± 114.6 ms, left AHAbd: 60.7 ± 70.5 vs. 133.9 ± 98.6 ms) occurred significantly later in individuals with rLBP than in individuals without rLBP (p < 0.01). During the left AHAbd test, the ipsilateral erector spinae was also activated significantly later in individuals with rLBP than in individuals without rLBP (71.1 ± 80.1 vs. 163.8 ± 120.1 ms, p < 0.05). No significant difference was observed in the onset of the external oblique activation on the right and left AHAbd tests (p > 0.05).ConclusionsOur results suggest that individuals with rLBP possess a trunk muscle activation pattern that is different from that of individuals without rLBP. These findings provide an insight into the underlying muscle activation patterns during the AHAbd test for people with rLBP and may support aggressive early intervention for neuromuscular control.

Trunk and hip muscles activation patterns in subjects with and without chronic low back pain: a systematic review

The purpose of this study was to determine normal and abnormal patterns of activation of gluteus maximus (GM), hamstring (HAM), contralateral erector spinae (CES), and ipsilateral erector spinae (IES) muscles during a prone hip extension test in healthy or asymptomatic subjects and those with non-specific chronic low back pain through a systematic review. Studies were recognized by searching electronic databases (Embase, MEDLINE/PubMed, Cochrane Library, PEDro [Physiotherapy Evidence Database], and CINAHL) and scanning articles reference lists from the beginning until July 2018. Limits involved studies in the English language and performed among humans. Of 2112 citations and reference lists scanned, 15 articles were determined to be relevant to this review. From these studies, 4 investigated 157 subjects (88 asymptomatic and 69 with low back pain), and 11 investigated 257 healthy subjects. The results of the moderate and weak quality studies indicate that the HAM and ES muscles are activated early and almost simultaneously, but GM is consistently delayed in relation to leg movement and the other 3 muscles in healthy individuals. In low back pain subjects, CES are delayed and GM is significantly delayed in individuals who showed abnormal lumbar motions when compared with healthy ones.

Effect of abdominal drawing-in maneuver with prone hip extension on muscle activation of posterior oblique sling in normal adults.

[Purpose] There have been many studies on ipsilateral erector spinae in regard of prone hip extension (PHE). However, mediating methods have been focusing on the reinforcement of gluteus. Hereupon, this study is intended to identify how an increase of abdominal drawing-in maneuver influences on posterior oblique sling (POS) and suggest a mediating method to effectively reinforce them. [Participants and Methods] This study has been conducted on normal male (10) and female (10), and participants were asked to prove PHE exercise and abdominal drawing-in maneuver prone hip extension exercise (ADIM PHE). Surface electromyography (EMG) was recorded from the contralateral latissimus dorsi, ipsilateral erector spinae, ipsilateral gluteus maximus, and ipsilateral biceps femoris. A pared t-test was used to compare muscle activity POS. [Results] EMG activity of the contralateral latissimus dorsi, ipsilateral gluteus maximus was significantly greater performed ADIM PHE than PHE. As for ipsilateral erector spinae muscle, ipsilateral biceps femoris activation was lower in ADIM PHE than PHE. [Conclusion] According to the results of this study, abdominal drawing-in maneuver seems to be an important factor that influences on muscular activation of POS.

Effect of reactive oxygen species of the psoas major muscle in complete Freund's adjuvant-induced inflammatory pain in rats.

Lower limb pain is a common clinical disease that affects millions of people worldwide. It is found in previous studies that reactive oxygen species is closely related to neuropathic, cancer, chemotherapy, and inflammatory pain, which can be relieved by reactive oxygen species scavengers. Furthermore, acupuncture or electroacupuncture on the psoas major muscle has a great effect on adjuvant-induced arthritis and lower back pain. In our study, we investigated the function of reactive oxygen species scavengers locally injecting into the ipsilateral psoas major muscle on complete Freund’s adjuvant-induced inflammatory pain. Our results demonstrated that in the development of complete Freund’s adjuvant-induced inflammatory pain, early local continuous application of N-tert-Butyl-α-phenylnitrone (PBN, 1 and 5 mg/kg/0.2 ml) on the ipsilateral psoas major muscle effectively reduced mechanical and cold hyperalgesia. However, intraperitoneal injection of PBN (1 and 5 mg/kg) or local injection of PBN (1 and 5 mg/kg/0.2 ml) into contralateral psoas major muscle, ipsilateral quadratus lumborum, and ipsilateral erector spinae showed limited effect. In the developed inflammatory pain model, local injection of PBN into the ipsilateral psoas major muscle also alleviated pain and paw edema. In addition, reactive oxygen species level increased in ipsilateral psoas major muscle at seven days after complete Freund’s adjuvant injection. In general, PBN reduces complete Freund’s adjuvant-evoked inflammatory pain by inhibiting reactive oxygen species in the psoas major muscle.

Association between lumbopelvic motion and muscle activation in patients with non-specific low back pain during forward bending task: A cross-sectional study.

Background:Evidence suggests patients with non-specific low back pain (NSLBP) have altered lumbar and pelvic movement patterns. These changes could be associated with altered patterns of muscle activation.Objective:The study aimed to determine: (1) differences in the relative contributions and velocity of lumbar and pelvic movements between people with and without NSLBP, (2) the differences in lumbopelvic muscle activation patterns between people with and without NSLBP, and (3) the association between lumbar and pelvic movements and lumbopelvic muscle activation patterns.Methods:Subjects (8 healthy individuals and 8 patients with NSLBP) performed 2 sets of 3 repetitions of active forward bending, while motion and muscle activity data were collected simultaneously. Data derived were lumbar and pelvic ranges of motion and velocity, and ipsilateral and contralateral lumbopelvic muscle activities (internal oblique/transverse abdominis (IO/TA), lumbar multifidus (LM), erector spinae (ES) and gluteus maximus (GM) muscles).Results:Lumbar and pelvic motions showed trends, but exceeded 95% confidence minimal detectable difference MDD, for greater pelvic motion , less lumbar motion among patients with NSLBP. Significantly less activity was observed in the GM muscles bilaterally in the NSLBP group. A significant association , was found between ipsilateral ES muscle activity and lumbar motion, while moderate, but statistically non-significant associations, were found between GM muscle activity bilaterally and lumbar velocity ipsilateral: , ; contralateral: , in the NSLBP group.Conclusion:Findings indicated patients had greater pelvic contribution, but less lumbar contribution which was associated with less activation of the GM bilaterally.

Hip and Trunk Muscle Activity During the Star Excursion Balance Test in Healthy Adults.

Dynamic balance is a measure of core stability. Deficits in the dynamic balance have been related to injuries in the athletic populations. The Star Excursion Balance Test (SEBT) is suggested to measure and improve dynamic balance when used as a rehabilitative tool. To determine the electromyographic activity of the hip and the trunk muscles during the SEBT. Descriptive. University campus. Twenty-two healthy adults (11 males and 11 females; 23.3 [3.8]y, 170.3 [7.6]cm, 67.8 [10.3]kg, and 15.1% [5.0%] body fat). Surface electromyographic data were collected on 22 healthy adults of the erector spinae, external oblique, and rectus abdominis bilaterally, and gluteus medius and gluteus maximus muscle of the stance leg. A 2-way repeated measures analysis of variance was used to determine the interaction between the percentage maximal voluntary isometric contraction (%MVIC) and the reach directions. The %MVIC for each muscle was compared across the 8 reach directions using the Sidak post hoc test with α at .05. %MVIC. Significant differences were observed for all the 8 muscles. Highest electromyographic activity was found for the tested muscles in the following reach directions-ipsilateral external oblique (44.5% [38.4%]): anterolateral; contralateral external oblique (52.3% [40.8%]): medial; ipsilateral rectus abdominis (8% [6.6%]): anterior; contralateral rectus abdominis (8% [5.3%]): anteromedial; ipsilateral erector spinae (46.4% [20.2%]): posterolateral; contralateral erector spinae (33.5% [11.3%]): posteromedial; gluteus maximus (27.4% [11.7%]): posterior; and gluteus medius (54.6% [26.1%]): medial direction. Trunk and hip muscle activation was direction dependent during the SEBT. This information can be used during rehabilitation of the hip and the trunk muscles.

Influence of muscle activation of posterior oblique sling from changes in activation of gluteus maximus from exercise of prone hip extension of normal adult male and female.

[Purpose] There have been many study ipsilateral erector spinae in regard of prone hip extension (PHE). However, mediating methods have been focusing on the reinforcement of gluteus. Hereupon, this study is intended to identify how an increase of gluteus maximus influences on posterior oblique sling (POS) and suggest a mediating method to effectively reinforce them. This study shows the seclective POS strength exercise. [Participants and Methods] This study has been conducted on normal male (13) and female (13), and participants were asked to proceed PHE exercise and prone hip extension with hip abduction with knee flexion (PHEAKF). Surface electromyography (EMG) was recorded from the contralateral latissimus dorsi, contralateral erector spinae, ipsilateral erector spinae, ipsilateral gluteus maximus, and ipsilateral biceps femoris. A paried t-test was used to compare muscle activity POS. [Results] EMG activity of the contralateral latissimus dorsi, ipsilateral erector spinae, and ipsilateral gluteus maximus was significantly greater performed PHEAKF than PHE. As for ipsilateral biceps femoris, muscle activation was lower in PHEAKF than PHE. [Conclusions] According to the results of this study, increase in muscular activation from the direction of muscular fiber and posterior oblique sling seems to be an important factor that influencontralateral crector spinae on muscular activation of POS.

Altered erector spinae activity and trunk motion occurs with moderate and severe unilateral hip OA.

People with hip osteoarthritis (OA) demonstrate altered movement patterns in the hip joint, as well as the pelvis and spine. While kinematic changes have been described in the literature, little is known about the associated erector spinae (ES) activity. Increased or prolonged ES activity may contribute to the low back pain often associated with hip OA. Using a cross-sectional cohort study, 3D trunk motions and ES surface electromyography were recorded on 19 individuals with severe OA (SOA), 20 with moderate hip OA (MOA), and 19 asymptomatic (ASYM) individuals during treadmill walking, using standardized collection and processing procedures. Principal component analysis was used to derive electromyographic amplitude and temporal waveform features. Three-dimensional thoracic motion in a global system, and thoraco-lumbar motion was calculated. Various statistical analyses determined between group differences (α = 0.05). In the sagittal plane, thoracic motion was greater in the SOA group (p < 0.001), whereas the ASYM group used less thoraco-lumbar motion than either OA group (p ≤ 0.002). Greater frontal plane angular excursion during early stance was found in the thoracic region in the SOA group (p ≤ 0.001) . With increasing OA severity, bilateral ES activity increased during the swing phase of gait (p < 0.001), whereas during stance, the SOA ipsilateral ES activity was higher than other groups (p < 0.001). Statement of clinical significance: with moderate and severe OA, sagittal, and frontal trunk motion increases during gait. ES activity during the entire gait cycle is more sustained with increased disease severity, which may aide our understanding of low back pain associated with hip OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1826-1832, 2018.

Effect of the Abdominal Hollowing and Bracing Maneuvers on Activity Pattern of the Lumbopelvic Muscles During Prone Hip Extension in Subjects With or Without Chronic Low Back Pain: A Preliminary Study

ObjectiveThe purpose of this study was to compare the effect of abdominal hollowing (AH) and abdominal bracing (AB) maneuvers on the activity pattern of lumbopelvic muscles during prone hip extension (PHE) in participants with or without nonspecific chronic low back pain (CLBP). MethodsTwenty women with or without CLBP participated in this cross-sectional observational study. The electromyographic activity (amplitude and onset time) of the contralateral erector spinae (CES), ipsilateral erector spinae (IES), gluteus maximus, and biceps femoris muscles was measured during PHE with and without abdominal maneuvers. A 3-way mixed model analysis of variance and post hoc tests were used for statistical analysis. ResultsBetween-group comparisons showed that the CES onset delay during PHE alone was greater (P = .03) and the activity level of IES, CES, and biceps femoris in all maneuvers (P < .05) was higher in patients with CLBP than in asymptomatic participants. In asymptomatic participants, PHE + AH significantly decreased the signal amplitude (AMP) of IES (P = .01) and CES (P = .02) muscles. In participants with CLBP, IES muscle AMP was lower during PHE + AH compared with PHE + AB and PHE alone. With regard to onset delay, the results also showed no significant difference between maneuvers within either of the 2 groups (P > .05). ConclusionsPerformance of the AH maneuver decreased the erector spinae muscle AMP in both groups, and neither maneuver altered the onset delay of any of the muscles in either group. The low back pain group showed higher levels of activity in all muscles (not statistically significant in gluteus maximus during all maneuvers). The groups were similar according to the onset delay of any of the muscles during either maneuver.

Bilateral experimental neck pain reorganize axioscapular muscle coordination and pain sensitivity.

Neck pain is a large clinical problem where reorganized trunk and axioscapular muscle activities have been hypothesised contributing to pain persistence and pain hypersensitivity. This study investigated the effects of bilateral experimental neck pain on trunk and axioscapular muscle function and pain sensitivity. In 25 healthy volunteers, bilateral experimental neck pain was induced in the splenius capitis muscles by hypertonic saline injections. Isotonic saline was used as control. In sitting, subjects performed slow, fast and slow-resisted unilateral arm movements before, during and after injections. Electromyography (EMG) was recorded from eight shoulder and trunk muscles bilaterally. Pressure pain thresholds (PPTs) were assessed bilaterally at the neck, head and arm. Data were normalized to the before-measures. Compared with control and post measurements, experimental neck pain caused (1) decreased EMG activity of the ipsilateral upper trapezius muscles during all but slow-resisted down movements (p<0.001), and (2) increased EMG activity in the ipsilateral erector spinae muscle during slow and fast movements (p<0.02), and in the contralateral erector spinae muscle during all but fast up and slow-resisted down movements (p<0.007). The PPTs in the painful condition increased at the head and arm compared with post measurements and the control condition (p<0.001). In the post-pain condition, the neck PPT was decreased compared with the control condition (p<0.001). Acute bilateral neck pain reorganized axioscapular and trunk muscle activity together with local hyperalgesia and widespread hypoalgesia indicating that acute neck pain immediately affects trunk and axioscapular function which may affect both assessment and treatment. Bilateral clinical neck pain alters axioscapular muscle coordination but only effects of unilateral experimental neck pain has been investigated. Bilateral experimental neck pain causes task-dependent reorganized axioscapular and trunk muscle activity in addition to widespread decrease in pressure pain sensitivity.

Individuals with chronic low back pain demonstrate delayed onset of the back muscle activity during prone hip extension

Prone hip extension (PHE) is commonly used in the evaluation of the stability of the lumbopelvic region. There is little evidence of difference in muscle activity onset timing between healthy individuals and individuals with chronic low back pain (CLBP) during PHE. The purpose of this study was to determine if individuals with and without CLBP differ in the onset time of the trunk and hip extensor muscles activity during PHE. The participants were 20 patients with CLBP and 20 healthy individuals. Electromyography data of the erector spinae, multifidus, gluteus maximus, and semitendinosus were collected during PHE using a surface electromyograph. Relative differences in the onset times between each muscle and the prime mover (i.e., the semitendinosus) were calculated. The onsets of the bilateral multifidus and contralateral erector spinae were significantly delayed in the CLBP group compared with the healthy group (p<0.001), despite the onset timings of leg movement not being significantly different between the groups. The onset times of the gluteus maximus and ipsilateral erector spinae showed no significant differences between the groups. These results suggest that individuals with CLBP use an altered, and possibly inadequate, trunk muscle recruitment pattern.

The biomechanics of running in athletes with previous hamstring injury: A case-control study.

Hamstring injury is prevalent with persistently high reinjury rates. We aim to inform hamstring rehabilitation by exploring the electromyographic and kinematic characteristics of running in athletes with previous hamstring injury. Nine elite male Gaelic games athletes who had returned to sport after hamstring injury and eight closely matched controls sprinted while lower limb kinematics and muscle activity of the previously injured biceps femoris, bilateral gluteus maximus, lumbar erector spinae, rectus femoris, and external oblique were recorded. Intergroup comparisons of muscle activation ratios and kinematics were performed. Previously injured athletes demonstrated significantly reduced biceps femoris muscle activation ratios with respect to ipsilateral gluteus maximus (maximum difference -12.5%, P = 0.03), ipsilateral erector spinae (maximum difference -12.5%, P = 0.01), ipsilateral external oblique (maximum difference -23%, P = 0.01), and contralateral rectus femoris (maximum difference -22%, P = 0.02) in the late swing phase. We also detected sagittal asymmetry in hip flexion (maximum 8°, P = 0.01), pelvic tilt (maximum 4°, P = 0.02), and medial rotation of the knee (maximum 6°, P = 0.03) effectively putting the hamstrings in a lengthened position just before heel strike. Previous hamstring injury is associated with altered biceps femoris associated muscle activity and potentially injurious kinematics. These deficits should be considered and addressed during rehabilitation.

Asymmetrical trunk muscle activities and kinematics during dominant and nondominant leg lifts in subjects with lumbar rotation with flexion syndrome

BACKGROUND: Patients with lower back pain due to lumbar rotation with flexion syndrome (LRFS) have greater asymmetry of rotation in the lumbopelvic region than healthy people. OBJECTIVE: To understand the activities of the trunk muscle and kinematics of the trunk and pelvis in patients with LRFS during the bird-dog (BD) exercise with dominant non-dominant leg lifts, a frequently prescribed stabilization exercise. METHODS: We compared activity and kinematics during the BD exercise with dominant and non-dominant leg lifts in 11 patients (6 male, 5 female) with LRFS who were recruited from a university. RESULTS: Significantly lower activation of the ipsilateral erector spinae muscle was found during the nondominant leg lift than the dominant leg lift in patients performing the BD exercise (t = −3.71, p = 0.04). In addition, the trunk was significantly flexed during the dominant leg lift (t = −6.069, p = 0.00) and bent to the right side (t = 3.131, p = 0.01) during both dominant and nondominant leg lifts. CONCLUSIONS: These results imply the presence of asymmetrical muscle activity and kinematics in the trunks of subjects with LRFS. This information should be considered for prescribing exercises to such subjects.

The Influence of an Unstable Surface on Trunk and Lower Extremity Muscle Activities during Variable Bridging Exercises.

[Purpose] The aim of this study was to investigate the influence of an unstable surface on trunk and lower extremity muscle activities during various types of bridging exercises. [Subjects] Thirty healthy female adults voluntarily participated in this study. [Methods] All subjects were asked to perform 3 different bridging exercises (bridging exercise, single leg lift bridging exercise, single leg cross bridging exercise) with and without an unstable surface. The trunk and lower extremity muscle activities were measured by using surface electromyography during bridging exercise. [Results] During the bridging exercise (BE), single leg lift bridging exercise (LBE), and single leg cross bridging exercise (CBE), the muscle activities of the external oblique muscle (EO), erector spinae (ES), and biceps femoris (BF) were significantly higher on an unstable surface than on a stable surface. The muscle activities of the EO on both sides, contralateral BF, and ipsilateral ES were significantly higher during LBE than during BE and CBE. [Conclusion] Use of an unstable surface increases muscle activity of the trunk and lower extremities, and single leg lift bridging exercise increases the muscle activity of the EO on both sides, ipsilateral ES, and contralateral BF.

Adaptation of muscles of the lumbar spine to sudden imbalance in patients with lower back pain caused by military training

ObjectiveThis study aims to investigate the effects of sudden load changes (expected and unexpected imbalance) on the activity of muscles of the lumbar spine and their central motor control strategy in military personnel with or without chronic low back pain (LBP).DesignBilateral sudden imbalance was examined (2 × 2 factorial design).SettingThe 117th PLA Hospital, Hangzhou, ChinaParticipantsTwenty-one male subjects with lower back pain and 21 male healthy control subjects were active members of the Nanjing Military Region land forces.Outcome measuresIndependent variables: LBP vs. healthy controls and imbalance anticipation (expected and unexpected imbalance). Dependent variables: rapid reaction time (RRT) and intensity of rapid reaction (IRR) of bilateral lumbar (L3–L4) erector spinae (ES), lumbar (L5–S1) multifidus (MF), and abdominal external oblique muscles.ResultsUnder expected or unexpected sudden imbalance conditions, subjects with LBP demonstrated significantly greater IRR than healthy controls in ipsilateral and contralateral ES and MF, respectively (P < 0.05 for all). IRR of contralateral ES was significantly larger than that of the ipsilateral ES. A significant group effect of RRT of both ipsilateral and contralateral ES muscles and a significant time expectation effect on RRT of contralateral MF muscles were also observed. RRT of the contralateral ES muscles was significantly lower than that of the ipsilateral ES muscles (P < 0.001).ConclusionsSudden imbalance prolonged RRT of selected trunk muscles in patients with chronic LBP. The activation amplitude increased. The results may provide a theoretical basis for a study on the pathogenesis of chronic LBP.

Comparison of Posterior Oblique Sling Activity during Hip Extension in the Prone Position on the Floor and on a Round Foam Roll

[Purpose] The aim of this study was to compare muscle activity of the posterior oblique sling during prone hip extension (PHE) on the floor and on a round foam roll. [Subjects] Twenty-two (11 male, 11 female) healthy volunteers were recruited for this study. [Methods] The participants performed PHE on the floor and on a round foam roll. Surface electromyography (EMG) was recorded from the contralateral latissimus dorsi (LD), contralateral erector spinae (ES), ipsilateral ES, ipsilateral gluteus maximus (GM), and ipsilateral biceps femoris (IBF). A paired t-test was used to compare muscle activity under the floor and round foam roll conditions. [Results] EMG activity of the contralateral LD, ipsilateral ES, and ipsilateral GM was significantly greater when PHE was performed on the round foam roll than on the floor. [Conclusion] Performing PHE on the round foam roll induced greater posterior oblique sling EMG activity than did exercise on the floor. These results suggest that the activation pattern of the posterior oblique sling during PHE is differs according to the type of surface (stable vs. unstable) on which it is performed.