Iliocostalis Research Articles

Physical Function and Low Back Pain in Leek Farmers: A Comparison with Non-Farmers

The purpose of this study was to investigate the low back pain (LBP) and physical function of young to middle aged farmers of leeks in western Tottori Prefecture.Fifteen farmers (55 years old or younger) cultivating leeks in western Tottori Prefecture were recruited as the subjects, and 14 non-farmers matching the age and sex of the subjects were recruited as the control group. A questionnaire survey was conducted to determine the presence or absence of LBP, smoking, and alcohol consumption. Physical functions were measured by anthropometry (body fat percentage and muscle mass), Finger-Floor distance (FFD), back muscle strength, and upper body bending, and lumbar muscle cross-sectional area (CSA) was evaluated by magnetic resonance imaging (MRI).Weight, BMI, body fat percentage, upper body bending, back muscle strength, and L3/4 iliocostalis lumborum CSA, current LBP were significantly higher in the leek farmer group. One-way analysis of variance showed significant differences in upper body bending, and history of LBP.LBP was more common among leek farmers. The characteristics of leek farmers with LBP were history of LBP.

The Relationship of Trunk Muscle Activation and Core Stability: A Biomechanical Analysis of Pilates-Based Stabilization Exercise.

Pilates is an effective exercise method for rehabilitating musculoskeletal disorders as its principles are based on the activation of local muscles. This study aimed to compare the subjects with and without Pilates experience to find out the effect of the experience on the core muscle activity and muscle co-contraction, and to examine the relationship between the core muscle activation level and the kinematic data. This study involved 32 subjects, including 16 experienced Pilates practitioners and 16 non-experienced subjects. The knee stretch on the reformer was performed in three different positions: flat back with a neutral pelvis, round back with posteriorly tilted pelvis (RPP), and extended back anteriorly tilted pelvis (EAP). The electromyography of the internal oblique (IO), rectus abdominis (RA), multifidus (MU), and iliocostalis lumborum (IL) muscles were measured, as well as kinematic data from a 3D motion analysis system. Compared to the non-experienced subjects, the experienced subjects activated the IO muscles more than the RA muscles, and the most significant difference was seen in the RPP position (p < 0.05). The experienced patients activated the MU muscles more often than the IL muscles, with the most significant difference observed in the RPP position and the least significant in the EAP position (p < 0.05). All kinematic data and muscle activity (IO, IO/RA ratio, MU/IL ratio) showed significant differences between the experienced and non-experienced subjects (p < 0.05). The subjects presented a moderate correlation between muscle activation and core stability. It was confirmed that the experienced Pilates practitioners activated the abdominal and low back core muscles effectively, and the stability of the pelvis and trunk were better than that of the non-experienced participants. In addition, the better the trunk stability was maintained, the larger and more accurate movement of the mobility segment was observed.

Comparison of Muscle Activity of the Erector Spinae according to Thoracic Spine Extension Mobility

Background During trunk extension, the thoracic extensor is decreased and the lumbar extensor is excessively activated, which is a factor inducing low back pain. Purpose The purpose of this study is to compare the muscle activity of the erector spinae of the thoracis and the lumborum during trunk extension according to the thoracic spine extension mobility. Study design Cross-sectional study. Methods 94 participants measured thoracic spine extension mobility and assigned low mobility group (n=31) and high mobility group (n=31) according to the mean and standard deviation. The muscle activity of the erector spinae was measured when participants maintained their trunk extension at the prone position. An independent <italic>t</italic>-test was used to compare the muscle activity between the low and high mobility groups. Results The muscle activity of longissimus thoracis, the ratio of longissimus thoracis:iliocostalis lumborum pars lumborum, and iliocostalis lumborum pars thoracis:iliocostalis lumborum pars lumborum was significantly different between the high and low mobility group (<italic>p</italic>&lt;0.05). Conclusions The muscle activity of longissimus thoracis and ratio between the thoracis and the lumborum of the erector spinae are reduced in the low mobility group than the high mobility group during trunk extension.

Botulinum toxin injection in longissimus and iliocostalis muscles for treating pisa syndrome: Short- and long-term effect

Pisa syndrome (PS), a reversible 310° lateral trunk flexion, is a frequent complication of Parkinson's disease (PD). Botulinum toxin (BoNT) showed preliminary short-term efficacy in PS. However, the best muscles to target remain unclear. We sought to analyze the efficacy of BoNT in PS targeting specific paraspinal muscles ipsilateral to the trunk flexion side.

Dynamic evaluation of the contractile function of lumbodorsal muscles during locust pose in yoga by real-time ultrasound

Background and PurposeChronic low back pain (CLBP), which has a close relationship with lumbar muscle degeneration, can be effectively treated by exercise therapy, and yoga has been widely accepted by clinicians and patients with CLBP. The purpose of this study was to observe the changes in the thickness of lumbodorsal muscles that occur during locust pose in yoga and how these changes occur. From the changes in muscle thickness that occur in the locust pose, the contractile function of lumbodorsal muscles can be evaluated.MethodsFifty-two healthy volunteers (from May 2019 to August 2019, age from 28 to 68 years, 23 males and 29 females (age: 40 ± 8 years; weight: 68.3 ± 5.2 kg; height: 170.2 ± 13.1 cm) were recruited, and lumbodorsal muscle, including the multifidus, longissimus, iliocostalis, and quadratus lumborum, ultrasonic examinations were carried out in the relaxed and contracted states. The changes in the thickness of the lumbodorsal muscles in the relaxed and contracted states were dynamically observed by real-time ultrasound when subjects were performing the locust yoga pose. Then, the thicknesses of the muscles during the two states were measured to calculate the ratio of contraction of each muscle and determine the statistical significance of the change in thickness of each muscle.ResultsThe mean thickness of the left multifidus in the relaxed state was 1.32 ± 0.27 cm (95 % CI: 1.24 ~ 1.39), that in the contracted state was 1.60 ± 0.30 cm (95 % CI: 1.52 ~ 1.69) (obviously different between the relaxed and contracted states, P < 0.001), and those in the corresponding right side were 1.37 ± 0.31 cm (95 % CI: 1.29 ~ 2.46) and 1.68 ± 0.38 cm (95 % CI: 1.58 ~ 1.79) (P < 0.001), respectively. The mean thickness of the left quadratus lumborum in the relaxed state was 1.38 ± 0.32 cm (95 % CI: 1.29 ~ 1.47), that in the contracted state was 1.62 ± 0.40 cm (95 % CI: 1.50 ~ 1.73) (P = 0.001), and those in the corresponding right side were 1.30 ± 0.32 cm (95 % CI: 1.21 ~ 1.39) and 1.55 ± 0.41 cm (95 % CI: 1.44 ~ 1.67) (P = 0.001), respectively. The mean thickness of the left longissimus in the relaxed was 2.33 ± 0.51 cm (95 % CI: 2.19 ~ 2.47), that in the contracted state was 3.20 ± 0.61 cm (95 % CI: 3.03 ~ 3.37) (P < 0.001), and those in the corresponding right side were 2.34 ± 0.49 cm (95 % CI 2.20 ~ 2.48) and 3.26 ± 0.68 cm (95 % CI 3.07 ~ 3.45) (P < 0.001), respectively. The mean thickness of the left iliocostalis in the relaxed state was 1.88 ± 0.41 cm (95 % CI: 1.76 ~ 1.99), that in the contracted state was 2.34 ± 0.49 cm (95 % CI: 2.00 ~ 2.47) (P < 0.001), and those in the corresponding right side were 1.98 ± 0.40 cm (95 % CI: 1.87 ~ 2.09) and 2.44 ± 0.56 cm (95 % CI: 2.29 ~ 2.60) (P < 0.001), respectively. The mean contracted state/resting state (C/R) of the longissimus was 1.39 ± 0.14 on the left and 1.40 ± 0.16 on the right. The multifidus and iliocostalis had the second highest C/R. The mean C/R of the multifidus was 1.23 ± 0.12 on the left and 1.24 ± 0.15 on the right, and the mean C/R of the iliocostalis was 1.25 ± 0.12 on the left and 1.24 ± 0.14 on the right. The quadratus lumborum had the lowest C/R, and the mean C/R of the quadratus lumborum was 1.17 ± 0.10 on the left and 1.19 ± 0.11 on the right.ConclusionsUltrasound can be used to dynamically assess the contractile function of the lumbar muscle in the locust pose of yoga, the C/R ratio can be used to indicate the ability of a muscle to contract, and dynamic ultrasound can guide lumbar exercise and feedback the exercise results. The establishment of this model allowed data regarding the contraction state of the lumbar muscle to be obtained in a normal population, and based on this, future studies can further explore and evaluate the contraction state of the lumbar muscle after yoga exercise in CLBP patients, the effect exercise on lumbar instability and on a patient population after lumbar operation.

Quantification of muscles activations and joints range of motions during oil palm fresh fruit bunch harvesting and loose fruit collection

Although global demand for palm oil has been increasing, most activities in the oil palm plantations still rely heavily on manual labour, which includes fresh fruit bunch (FFB) harvesting and loose fruit (LF) collection. As a result, harvesters and/or collectors face ergonomic risks resulting in musculoskeletal disorder (MSD) due to awkward, extreme and repetitive posture during their daily work routines. Traditionally, indirect approaches were adopted to assess these risks using a survey or manual visual observations. In this study, a direct measurement approach was performed using Inertial Measurement Units, and surface Electromyography sensors. The instruments were attached to different body parts of the plantation workers to quantify their muscle activities and assess the ergonomics risks during FFB harvesting and LF collection. The results revealed that the workers generally displayed poor and discomfort posture in both activities. Biceps, multifidus and longissimus muscles were found to be heavily used during FFB harvesting. Longissimus, iliocostalis, and multifidus muscles were the most used muscles during LF collection. These findings can be beneficial in the design of various assistive tools which could improve workers' posture, reduce the risk of injury and MSD, and potentially improve their overall productivity and quality of life.

The effect of extensible and non-extensible lumbosacral orthoses on anticipatory postural adjustments in participants with low back pain and healthy controls

BackgroundWearing a lumbosacral orthosis (LSO) is known to influence spine mechanics, but less is known about how LSOs affect motor control. Whether the use of a LSO can negatively affect motor control of the lumbar spine is still under debate. ObjectiveThe current study examined the immediate effects of two flexible LSOs (extensible and non-extensible) on the anticipatory postural adjustments that prepare the spine for a predictable perturbation. DesignA comparative study using a repeated measures design in a laboratory setting. MethodsHealthy controls (n = 20) and participants with low back pain (n = 40) performed a rapid arm flexion/extension cycle with and without these LSOs. The latency between the activations of the shoulder and different back (iliocostalis lumborum) and abdominal (rectus abdominis, internal and external obliques) muscles, as measured with surface electromyography, was used as the outcome. ResultsThe effects, which were comparable between groups and between LSOs, were mixed, with some muscles showing significantly (p ˂ 0.05) earlier activation and others showing delayed activation with the use of a LSO, relative to the control condition. The corresponding effect sizes were low to average (Hedges's g range: 0.17–0.48). ConclusionsThese findings suggest a change in the motor program before task initiation, which might be generalizable to other activities of daily living or work. However, none of the effects were large, making it difficult to provide clear conclusions with regard to their clinical relevance. It remains to be tested whether these immediate adaptations in motor planning can induce long term detrimental effects to the control of lumbar stability.

Reliability of lumbar multifidus and iliocostalis lumborum thickness and echogenicity measurements using ultrasound imaging.

To establish the test-retest and inter-rater reliability of lumbar multifidus (LM) and iliocostalis lumborum (IL) muscle thickness and echogenicity as derived using ultrasound imaging. Ultrasound images of the LM and IL were collected from 11 healthy participants on two occasions, 1week apart, by two independent assessors. Measures of LM and IL thickness and echogenicity were subject to test-retest and inter-rater reliability, which was assessed by calculation of an F statistic, the interclass correlation coefficient (ICC), the standard error of measurement, 95% confidence intervals and Bland-Altman plots. This study was given approval by The University of Melbourne Behavioural and Social Sciences Human Ethics Sub-Committee (ref: 1749845). Assessors A and B showed good to excellent test-retest reliability for LM thickness (ICC3,3 A: 0.89 and B: 0.98), LM echogenicity (ICC3,3 A: 0.93 and B: 0.95) and IL echogenicity (ICC3,3 A: 0.87 and B: 0.83). Test-retest reliability for IL thickness was poor for Assessor A but excellent for Assessor B. Both assessors demonstrated excellent inter-rater reliability for LM thickness and echogenicity (ICC2,3: 0.79 and 0.94), but poor reliability for IL thickness and echogenicity (ICC2,3: 0.00 and 0.39). Inter-rater and test-retest reliability was excellent for LM but was less reliable for measures of the IL muscle.

Fetal development and growth of the human erector spinae with special reference to attachments on the surface aponeurosis.

The longissimus (LO) and iliocostalis (IC) of adults consist of myofibers extending from the superolateral to the inferomedial side of the back and, because of the same course, they are fused in the thoracolumbar region. The LO also has a medial attachment to the long myofibers of the transversospinalis (TS) showing a course from the superomedial to the inferolateral side. However, there is apparently no information regarding when and how these similar longitudinal muscles differentiate from a cluster of dorsomedial myotome cells. We examined sagittal and horizontal sections of the trunks of 39 human embryos and fetuses (18-330mm crown-rump length). At 6-7weeks gestational age (GA), the surface aponeurosis appeared prior to and independent of the thoracolumbar fascia. At 6-9weeks GA, the LO myofibers had a postero-inferior course, from the transverse process to the initial aponeurosis, whereas the TS myofibers had a postero-superior course, from a lateral extension of the intertransverse ligament to the aponeurosis. However, the IC consisted of supracostal longitudinal myofibers and was distant from the LO until 12weeks GA. Because of the lack of ligamentous attachments and ribs, myofibers of the TS, LO, and IC took a similar inferior course in the lumbar region. When the early TS was represented by the transverso-aponeurotic muscle, consequently, the LO corresponded to the aponeuro-transversal muscle and was independent from the IC. The classical model of TS and LO development does not recognize the essential role of the aponeurosis identified here.

The effects of prolonged sitting, standing, and an alternating sit-stand pattern on trunk mechanical stiffness, trunk muscle activation and low back discomfort

Sit-stand desks continue to be a popular intervention for office work. While previous studies have reported changes in subjective measures, there is limited understanding of how sit-stand work differs from prolonged sitting or standing work, from a biomechanical standpoint. The objective of this study was to investigate the effects of prolonged sitting, prolonged standing, and a sit-stand paradigm on changes in trunk stiffness, low back discomfort, and trunk muscle activation. Twelve healthy participants performed 2 h of computer-based tasks in each protocol, on three different days. The sit-stand protocol was associated with a significant increase in trunk stiffness and a decrease in muscle activation of lumbar multifidus and longissimus thoracis pars thoracis, compared to both prolonged sitting and standing. Both sitting and standing were associated with increased low back discomfort. These findings may be worth exploring in more detail, for why alternating sit-stand patterns may help alleviate low back pain. Practitioner summary: We explored changes in objective and subjective measures related to low back discomfort following prolonged sitting, standing, and alternating sit-stand patterns. Alternating sit-stand pattern was associated with increased trunk stiffness and decreased back muscle activity. Hence, sit-stand desks may have benefits in terms of preventing/mitigating low back pain. Abbreviations: DOF: degree of freedom; EMG: electromyogram; ILL: iliocostalis lumborum pars lumborum; LTL: longissimus thoracis pars lumborum; LTT: longissimus thoracis pars thoracis; LBP: low back pain; LM: lumbar multifidus; MVEs: maximum isometric voluntary exertions; RANOVA: repeated-measure analysis of variance; RMS: root mean square

Muscular blood oxygen level-dependent MRI is beneficial to evaluate effectiveness of an exercise prescription

BackgroundTo determine the feasibility and validity of using blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) to evaluate the effects of back extension exercise on core lumbar paraspinal muscle strength.MethodsIn this prospective study, R2* and T2 mapping of paraspinal muscles of 100 healthy volunteers were performed before and after back extension exercises in different recovery sessions (session I, II, III or IV). Volunteers use the Roman chair to complete the back extension exercises. The cross-sectional area (CSA), R2* and T2 values were measured and analyzed in 3 muscles (iliocostalis, longissimus, and multifidus muscles) of the lower back before and after exercise.ResultsThe CSA and T2 values of iliocostalis, longissimus, and multifidus muscles at L3 and L4 levels were higher in recovery sessions I and II than in the resting-state (P<0.05); however, compared to that in the resting-state, the R2* value was significantly reduced in session I but increased in sessions II–IV (P<0.05). Furthermore, the CSA and T2 values in recovery session I were higher than those in the resting-state, whereas the R2* value was lower (P<0.05). After exercise, the recovery tendency of R2* and T2 value was consistent in both males and females, but a significant sex difference in R2* value was observed between recovery sessions III and IV (P<0.05).ConclusionsR2* mapping and T2 mapping are effective and feasible for assessment of the effects of back extension exercises on lumbar paraspinal muscle strength.

Fetal development of the thoracolumbar fascia with special reference to the fascial connection with the transversus abdominis, latissimus dorsi, and serratus posterior inferior muscles.

The three-layered thoracolumbar fascia (TLF) encapsulates the erector spinae and the quadratus lumborum and has been a major concern for physical therapists. However, knowledge of its prenatal development and growth is limited. Histological examination of 25 embryos and fetuses at 6-37weeks (CRLs, 15-310mm). At the posterior end, the abdominal muscles continued toward an initial posterior layer of the TLF (pTLF) at 6weeks, but the connection became narrow and limited to the obliquus externus aponeurosis until near term. The middle layer of the TLF (mTLF) appeared as a posterior continuation of the transversalis fascia at 9weeks and, depending on a mechanical demand for the vertebral column extension near term, it grew as a thick intermuscular septum between the iliocostalis and quadratus lumborum. Thus, the mTLF lateral end changed from the abdominal wall to the back or pTLF. The serratus posterior inferior originated from the pTLF after 9weeks, but a connection of the latissimus dorsi with the fascia was established much later. Near term, the gluteus maximus was attached to an aponeurosis covering the multifidus behind the sacrum. Therefore, the pTLF extended to cover the gluteal muscles. We rejected the hypothesis that the mTLF develops as a marginal tissue between the primitive epaxial and hypaxial muscles. This study seemed to be the first report showing a fact that, within prenatal life, a drastic change is likely to occur in interfascial connections and their topographical relation to muscles; the TLF might be the best sample.

Effects of trunk extensor eccentric exercise on lipid profile and glycaemic response

ObjectivesA number of previous studies reported physiological responses and adaptations after eccentric muscle contraction of limb muscles. In contrast, no study has determined physiological response after eccentric contraction of trunk...

The immediate effect of the abdominal drawing-in maneuver technique on stature change in seated sedentary workers with chronic low back pain

Many studies have measured stature change arising from loads imposed on the spine during sitting. To improve stature recovery, it is important to stabilise the lumbar spine and compensate forces from the upper body. The abdominal drawing-in maneuver (ADIM) technique has been found to mainly activate deep trunk muscles. The purpose of this study was to determine whether activation of deep trunk muscles by the ADIM technique could immediately improve stature recovery during prolonged sitting. Twenty-four patients with chronic low back pain (CLBP) were randomly allocated into different orders of experimental conditions: control (sitting without ADIM technique) and intervention conditions (sitting with ADIM technique). The latter condition required participants to complete ADIM technique for 1 min and repeat it three times throughout 41 min prolonged sitting time. Stature recovery was improved by 3.292 mm in the intervention condition compared with control condition (p-value = 0.001). Our finding demonstrated that ADIM technique improved stature recovery. Practitioner Summary: Prolonged sitting seemingly harms sedentary workers’ health, particularly affecting the lower back. Activation of deep trunk muscles using abdominal drawing-in maneuver technique can promote spinal recovery. Clinicians can teach abdominal drawing-in maneuver technique to activate deep trunk muscles in chronic low back pain, thereby promoting self-management of seated stature recovery. Abbrevations: ADIM: abdominal drawing-in maneuver; RA: rectus abdominis; ICLT: iliocostalis lumborum pars thoracis; LM: lumbar multifidus; TrA: transversus abdominis; IO: internal oblique; CLBP: chronic low back pain; LBP: low back pain; RMDQ: Roland Morris disability questionnaire; NRS: numerical rating scale.

Ultrasound Shear Wave Elastography to Assess Tissue Mechanical Properties in Somatic Dysfunction: A Feasibility Study.

Diagnosis of somatic dysfunction is based on subjective palpatory osteopathic assessments. This subjectivity has posed a challenge for researchers in studying osteopathic medicine. The development and use of radiological imaging techniques to objectively confirm or quantify muscle tissue stiffness associated with somatic dysfunction could be of benefit in osteopathic clinical practice, training, and further research. To investigate the feasibility of ultrasound shear wave elastography (SWE) to quantify muscle tissue stiffness in somatic dysfunction before and after osteopathic manipulative treatment (OMT). In this prospective study, we assessed lumbar spine somatic dysfunction in 20 adult patients before and after a single OMT session using standard osteopathic palpatory assessments by osteopathic physician faculty members in the Department of Osteopathic Principle and Practice at Rocky Vista University College of Osteopathic Medicine (Utah campus). Shear wave velocity (SWV, m/s) was measured in lumbar paraspinal muscle tissue using a commercial ultrasonography scanner on all participants immediately before and after OMT. In this study, OMT techniques targeted the iliocostalis lumborum and included the articulatory technique, balanced ligamentous tension, facilitated positional release, high-velocity, low-amplitude technique, muscle energy, myofascial release, and the Still technique at the discretion of the osteopathic physician. The difference in SWV between muscle tissues with and without dysfunction, and differences in SWV of dysfunctional tissue before and after OMT were examined using unpaired and paired t tests, as appropriate. The correlation between SWV measurements and osteopathic assessments was examined by the Spearman rank correlation. Intra- and interobserver reliability was analyzed using intraclass correlation coefficient. The difference in SWV between muscle tissues with and without somatic dysfunction was significant before OMT (mean [SD], 1.93 [0.44] vs 1.69 [0.19]; P=.03) and was not significant after OMT (mean [SD], 1.69 [0.19] vs 1.53 [0.31]; P=.05). The difference in SWV in the same tissue with somatic dysfunction before and after OMT was significant (mean [SD], 1.93 [0.44] vs 1.52 [0.3]; P<.001). The SWV value highly correlated with manual osteopathic assessments (r=0.72). Intra- and interobserver reliability for performing SWE in somatic dysfunction was good (intraclass correlation coefficient >0.80). The results of this study show that ultrasound SWE can objectively assess muscle tissue stiffness for diagnosis of somatic dysfunctions and for muscle tissue stiffness changes after OMT.

Pre-stretching of the Hamstrings Before Squatting Acutely Increases Biceps Femoris Thickness Without Impairing Exercise Performance.

Background: Bilateral squat exercise is widely used in resistance training (RT) programs to increase lower limb strength and muscle mass, but this exercise does not result in significant hypertrophy of the hamstrings. It has been speculated that stretching between sets with a certain degree of tension results in muscle hypertrophy, while acute stretching could decrease performance during maximal contractions.Objective: This study investigated the acute effects of hamstring stretching before bilateral squatting on muscle thickness (MT), electromyography (EMG), and total training volume (TTV) on exercise performance.Methods: Fourteen resistance-trained young men, with ∼7.5 years of RT experience, performed the 10 repetition maximum (RM) for the barbell squat in two sessions (test–retest) separated by period after 48 h. Participants engaged in two resistance exercise conditions separated by a 1 week recovery interval: one session employed hamstrings stretching and the other did not include hamstrings stretching. Before and after each resistance exercise session, the thickness of the quadriceps muscles and biceps femoris long head were obtained by ultrasound imaging. Moreover, the EMG amplitudes for the quadriceps muscles, biceps femoris, and iliocostalis muscles were recorded during back squat performance. The TTV was also evaluated for each exercise session.Results: A significant increase in MT was observed after every set in both conditions for the evaluated quadriceps muscles (all p < 0.05), while for the biceps femoris, this effect was found only in the stretching condition (p < 0.05). EMG activity increased in the rectus femoris, vastus lateralis, and vastus medialis for the stretching condition. For the non-stretching condition, activity only increased in the vastus lateralis and medialis. There was no difference in EMG activity for the biceps femoris and iliocostalis in both conditions.Conclusion: Stretching the hamstrings immediately before each set of the back squat can be used to acutely increase biceps femoris thickness without impairing squat performance.

Neuromuscular activation analysis of the trunk muscles during hippotherapy sessions

IntroductionHippotherapy allows the development of affective, sensory, motor, and cognitive areas, besides providing the practitioner with several movements and stimuli necessary for therapeutic progress. However, there is a limited amount of scientific evidence regarding the suitability of the mount material, mount type, and hippotherapy session duration, as well as regarding the activation of specific muscle groups during the practice and its applicability to activities of daily living. ObjectiveThis study aimed to study the neuromuscular activation behavior of the iliocostalis, longissimus, multifidus, and upper trapezius muscles of children during four hippotherapy session time points using a functional task. It also compared two different mount materials for riding. MethodologyA total of 30 children were randomly assigned to one of three groups: Saddle Hippotherapy Group, Blanket Hippotherapy Group, and Control Group. Data were collected with an electromyograph in a functional task that comprised trunk movements to pick up an object. Assessments took place at four times during the session. ResultsThere was a significant increase in the neuromuscular activation of the iliocostalis, longissimus, and multifidus muscles after a 30-min session. The trapezius muscle showed increased neuromuscular activation after only 10 min. It continued to increase (but without a statistical difference) after and 20 and 30 min. ConclusionHippotherapy promoted neuromuscular activation of the trunk muscles in children, assessed through a functional task, and was influenced by both session time and mount material. Specifically, the greater neuromuscular performance occurred when an exercise was performed using saddle and stirrup and lasted 30 min.

Interpretable machine learning models for classifying low back pain status using functional physiological variables

PurposeTo evaluate the predictive performance of statistical models which distinguishes different low back pain (LBP) sub-types and healthy controls, using as input predictors the time-varying signals of electromyographic and kinematic variables, collected during low-load lifting.MethodsMotion capture with electromyography (EMG) assessment was performed on 49 participants [healthy control (con) = 16, remission LBP (rmLBP) = 16, current LBP (LBP) = 17], whilst performing a low-load lifting task, to extract a total of 40 predictors (kinematic and electromyographic variables). Three statistical models were developed using functional data boosting (FDboost), for binary classification of LBP statuses (model 1: con vs. LBP; model 2: con vs. rmLBP; model 3: rmLBP vs. LBP). After removing collinear predictors (i.e. a correlation of > 0.7 with other predictors) and inclusion of the covariate sex, 31 predictors were included for fitting model 1, 31 predictors for model 2, and 32 predictors for model 3.ResultsSeven EMG predictors were selected in model 1 (area under the receiver operator curve [AUC] of 90.4%), nine predictors in model 2 (AUC of 91.2%), and seven predictors in model 3 (AUC of 96.7%). The most influential predictor was the biceps femoris muscle (peak beta = 0.047) in model 1, the deltoid muscle (peak beta = 0.052) in model 2, and the iliocostalis muscle (peak beta = 0.16) in model 3.ConclusionThe ability to transform time-varying physiological differences into clinical differences could be used in future prospective prognostic research to identify the dominant movement impairments that drive the increased risk.Graphic abstractThese slides can be retrieved under Electronic Supplementary Material.

Age-specific differences in the time-frequency representation of surface electromyographic data recorded during a submaximal cyclic back extension exercise: a promising biomarker to detect early signs of sarcopenia

PurposeMotivated by the goal of developing new methods to detect early signs of sarcopenia, we investigated if surface electromyographic (SEMG) data recorded during the performance of cyclic, submaximal back extensions are marked by age-specific differences in their time and frequency characteristics. Furthermore, day-to-day retest reliability of the EMG measures was examined.MethodsA total of 86 healthy volunteers used a back dynamometer to perform a series of three maximal voluntary contractions (MVC) consisting of isometric back extensions, followed by an isometric back extension at 80% MVC, and finally 25 slow cyclic back extensions at 50% MVC. SEMG data was recorded bilaterally at L1, L2, and L5 from the iliocostalis lumborum, longissimus, and multifidus muscles, respectively. Tests were repeated two days and six weeks later. A linear mixed-effects model with fixed effects “age, sex, test number” and the random effect “person” was performed to investigate age-specific differences in both the initial value and the time-course (as defined by the slope of the regression line) of the root mean square (RMS-SEMG) values and instantaneous median frequency (IMDF-SEMG) values calculated separately for the shortening and lengthening phases of the exercise cycles. Generalizability Theory was used to examine reliability of the EMG measures.ResultsBack extensor strength was comparable in younger and older adults. The initial value of RMS-SEMG and IMDF-SEMG as well as the RMS-SEMG time-course did not significantly differ between the two age groups. Conversely, the IMDF-SEMG time-course showed more rapid changes in younger than in older individuals. Absolute and relative reliability of the SEMG time-frequency representations were comparable in older and younger individuals with good to excellent relative reliability but variable absolute reliability levels.ConclusionsThe IMDF-SEMG time-course derived from submaximal, cyclic back extension exercises performed at moderate effort showed significant differences in younger vs. older adults even though back extension strength was found to be comparable in the two age groups. We conclude that the SEMG method proposed in this study has great potential to be used as a biomarker to detect early signs of sarcopenic back muscle function.

Effects of Manual Therapy and Mechanical Massage on Spinal Alignment, Extension Range of Motion, Back Extensor Electromyographic Activity, and Thoracic Extension Strength in Individuals with Thoracic Hyperkyphosis: A Randomized Controlled Trial.

Background Manual therapy has been recommended to reduce and prevent musculoskeletal problems related to thoracic hyperkyphosis. With recent rapid technological developments, manual techniques can now be implemented by mechanical devices; hence, mechanical massage can manipulate the back muscles and mobilize the spine. Purpose Here, we aimed to 1) determine the effects of mechanical massage and manual therapy and 2) compare their effects on spinal posture, extension range of motion, trunk extensor electromyographic activity, and thoracic extension strength in individuals with thoracic hyperkyphosis. Methods Participants with thoracic hyperkyphosis were randomly assigned to the manual therapy (n = 16) or mechanical massage (n = 19) group. Each intervention was applied for 8 weeks. The participants' spinal posture, extension range of motion, trunk extensor electromyographic activity, and thoracic extension strength were measured before and after intervention. Results Intergroup analyses revealed no significant differences in any variables. However, thoracic kyphosis angle, thoracic extension range of motion, longissimus thoracis electromyographic activity, iliocostalis lumborum pars lumborum activity, and thoracic extension strength differed significantly in intertime analyses. The results of paired t-test analysis showed that thoracic kyphosis angle, thoracic extension range of motion, longissimus thoracis electromyographic activity, and thoracic extension strength were significantly different after intervention in both groups (p < 0.05). Conclusions Mechanical massage and manual therapy effectively improve thoracic kyphosis angle, thoracic extension range of motion, and thoracic extension strength. Therefore, mechanical massage is an alternative intervention to manual therapy for improving thoracic kyphosis angle, thoracic extension range of motion, and thoracic extension strength in participants with hyperkyphosis. This trail is registered with KCT0004527.