Contractions of specific abdominal muscles in postural tasks are affected by respiratory maneuvers

Pelvic floor muscle length changes with breathing in males: A preliminary report

The study aimed to identify whether pelvic floor muscles modulate length with breathing, and if any length changes induced by breathing relate to abdominal cavity displacement and intra-abdominal pressure. To investigate these relationships, displacement of pelvic landmarks that related to pelvic floor muscle length using transperineal ultrasound imaging, breath volume, intra-abdominal pressure, abdominal and ribcage displacement, and abdominal and anal sphincter muscle electromyography were measured during quiet breathing and breathing with increased dead-space in ten healthy men. Pelvic floor muscle landmark displacement modulated with ribcage motion during breathing. This relationship was stronger for: i) motion of the urethrovesical junction (puborectalis muscle length change) than the mid-urethra landmark (striated urethral sphincter muscle length change), and ii) dead-space breathing in standing than dead-space breathing in supine or quiet breathing in standing. In most (but not all) participants, the urethrovesical junction descended during inspiration and elevated during expiration. Striated urethral sphincter length changes during the respiratory cycle was independent of intra-abdominal pressure. In summary, breathing involves pelvic floor muscle length changes and is consistent with the role of these muscles during respiration to aid maintenance of continence, lung ventilation and/or provision of support to the abdominal cavity. Clinicians who train pelvic floor muscles need to be aware that length change of pelvic floor muscles is expected with breathing.

Emotional state as a modulator of autonomic and somatic nervous system activity in postural control: a review

Advances in our understanding of postural control have highlighted the need to examine the influence of higher brain centers in the modulation of this complex function. There is strong evidence of a link between emotional state, autonomic nervous system (ANS) activity and somatic nervous system (somatic NS) activity in postural control. For example, relationships have been demonstrated between postural threat, anxiety, fear of falling, balance confidence, and physiological arousal. Behaviorally, increased arousal has been associated with changes in velocity and amplitude of postural sway during quiet standing. The potential links between ANS and somatic NS, observed in control of posture, are associated with shared neuroanatomical connections within the central nervous system (CNS). The influence of emotional state on postural control likely reflects the important influence the limbic system has on these ANS/somatic NS control networks. This narrative review will highlight several examples of behaviors which routinely require coordination between the ANS and somatic NS, highlighting the importance of the neurofunctional link between these systems. Furthermore, we will extend beyond the more historical focus on threat models and examine how disordered/altered emotional state and ANS processing may influence postural control and assessment. Finally, this paper will discuss studies that have been important in uncovering the modulatory effect of emotional state on postural control including links that may inform our understanding of disordered control, such as that observed in individuals living with Parkinson's disease and discuss methodological tools that have the potential to advance understanding of this complex relationship.

Are respiratory disorders risk factors for troublesome neck/shoulder pain? A study of a general population cohort in Sweden

PURPOSE

The etiology of neck/shoulder pain is complex. Our purpose was to investigate if respiratory disorders are risk factors for troublesome neck/shoulder pain in people with no or occasional neck/shoulder pain.

METHODS

This prospective cohort study was based on the Stockholm Public Health Cohorts (SPHC) 2006/2010 and the SPHC 2010/2014. We included adults who at baseline reported no or occasional neck/shoulder pain in the last six months, from the two subsamples (SPHC 06/10 n = 15 155: and SPHC 2010/14 n = 25 273). Exposures were self-reported asthma at baseline in SPHC 06/10 and Chronic Obstructive Pulmonary Disease (COPD) at baseline in SPHC 10/14. The outcome was having experienced at least one period of troublesome neck/shoulder pain which restricted work capacity or hindered daily activities to some or to a high degree during the past six months, asked for four years later. Binomial regression analyses were used to calculate risk ratios (RR) with 95% confidence intervals (95% CI).

RESULTS

Adjusted results indicate that those reporting to suffer from asthma at baseline had a higher risk of troublesome neck/shoulder pain at follow-up four years later (RR 1.48, 95% CI 1.10-2.01) as did those reporting to suffer from COPD (RR 2.12 95%CI 1.54-2.93).

CONCLUSION

Our findings indicate that those with no or occasional neck/shoulder pain and reporting to suffer from asthma or COPD increase the risk for troublesome neck/shoulder pain over time. This highlights the importance of taking a multi-morbidity perspective into consideration in health care. Future longitudinal studies are needed to confirm our findings.

The relationship between the degeneration and asymmetry of the lumbar multifidus and erector spinae muscles in patients with lumbar disc herniation with and without root compression

BACKGROUND

The determination of muscle pathologies in lumbar disc herniation (LDH) and other conditions with low back pain is important for understanding low back problems and determining appropriate treatment methods. In patients with lumbar disc herniation with radiculopathy, elucidating the effect of root compression on the severity of muscle degeneration may predict the importance of alleviating root compression. For this purpose, magnetic resonance imaging (MRI) was used to compare the degeneration and asymmetries of the lumbar musculus multifidus (MF) and lumbar musculus erector spinae (ES) muscles in patients with lumbar discopathy without root compression (radiculopathy) and in patients with lumbar discopathy with root compression (radiculopathy).

METHODS

The patients were examined in two groups: 56 patients with lumbar discopathy and no radiculopathy (Non-rad group) and 51 patients with lumbar discopathy and radiculopathy (Rad group). On axial MRI sections passing through the centre of the disc at the L3-S1 level, the asymmetry, cross-sectional area (CSA), fat infiltration, and total CSA (TCSA = MF + ES) of the MF and ES muscles were measured and compared.

RESULTS

No difference was seen between the groups with respect to the CSA values of the right and left MF and left ES, but a significant difference was found in the right ES CSA (p = 0.021). The CSA and TCSA of the MF and ES showed no asymmetry according to group. Severe fat infiltration of > 50% in the right and left MF and left ES was found in the Rad group at a higher rate than in the Non-rad group. Fat infiltration was significantly positively correlated with age, body mass index, and the duration of pain (p < 0.001, p < 0.001, p = 0.004, respectively).

CONCLUSIONS

The study results showed a correlation between LDH and paraspinal muscle degeneration, while no correlation was found with asymmetry. Severe (> 50%) fat infiltration is associated with root compression, and the severity of fat filtration increases in the presence of root compression. The development of more severe degeneration due to denervation associated with root compression plays a role in the emergence of this situation. Therefore, in patients with lumbar disc herniation with radiculopathy, it can be foreseen that to stop and correct severe fat infiltration and muscle degeneration, first, nerve root compression should be corrected with appropriate medical treatment methods, and in patients in whom there is no response, the pressure should be alleviated with appropriate surgical methods.

Surface electromyographic activity of the erector spinae and multifidus during arm- and leg-ergometer exercises in young healthy men

Objectives: Ergometer exercise was considered a new loading method that can be used for participants who are unable to assume the core strengthening exercise posture commonly used to strengthen the erector spinae and multifidus. This study aimed to investigate with healthy participants whether arm and leg ergometers could be used for core strengthening exercises and whether different exercise sites would affect the results. Methods: The study was conducted with 15 healthy adult male participants aged 20-35 years. The intervention consisted of arm- and leg-ergometer exercises performed by the participants. The exercise protocol consisted of three 1-min sessions (rest, 50W, and 100 W), which were measured consecutively. Surface electromyography (sEMG) was measured during the sessions. Maximal voluntary contraction (MVC) of the erector spinae and multifidus was also measured, during which sEMG was measured. The sEMG during ergometer exercise was calculated as a percentage of the MVC (calculated as % MVC). The root mean square (RMS) was recorded from the sEMG activity. Muscle activity of the erector spinae and multifidus was compared between ergometer exercises and between intensity levels. Heart rate (HR) was recorded by electrocardiogram. Results: In the arm-ergometer exercise, the % MVC values of the erector spinae were 6.3 ± 3.1, 10.9 ± 5.4, and 16.9 ± 8.3% at rest, 50 W, and 100 W conditions, respectively. The multifidus was 4.6 ± 2.9, 9.2 ± 5.6, and 12.6 ± 7.6% at rest, 50 W, and 100 W conditions, respectively. The respective % MVC values during the leg-ergometer exercise were 3.8 ± 1.7, 7.2 ± 3.8, and 10.4 ± 4.0% at rest, 50 W, and 100 W conditions, respectively. Leg-ergometer exercises were 2.6 ± 2.1, 6.9 ± 5.7, and 10.3 ± 6.8% at rest, 50 W, and 100 W conditions, respectively. The activities of the two muscles increased at comparable levels with increased workload in both types of exercises (p < 0.01, each). HR increased with the increased workload and the increase was larger during arm-than leg-ergometer exercises. Conclusion: These results demonstrate that both arm- and leg-ergometer exercises are potentially alternative methods for erector spinae and multifidus training for healthy participants. Further research is needed to target elderly.

Is the diaphragm thickness related to gait speed in patients with hemiplegia caused by cerebrovascular accident?

[Purpose] We aimed to determine the relationship between gait speed and diaphragm thickness in community-residing patients with hemiplegia caused by cerebrovascular accidents. [Participants and Methods] We recruited 11 elderly participants (six male and five female, mean age 71.1 ± 13.6 years) from an outpatient rehabilitation unit. The inclusion criteria were as follows: patients with hemiplegia caused by cerebrovascular accidents, those able to walk without assistance, and those able to understand our instructions. We measured the diaphragm thickness on both the paretic and non-paretic sides in each participant during maximum exhalation and inhalation during three laboured breaths by ultrasonography with a 7.5-MHz linear scanner. The liner scanner was placed on the eighth or ninth rib between the anterior and middle axillary lines. And their gait speed was measured during a 10 m walk. [Results] There was a strong positive correlation between gait speed and the ratio of diaphragm thickness between the paretic and the non-paretic sides during maximal inspiration. The other measured parameters did not show significant correlation with gait speed. [Conclusion] The symmetrical thickness of the diaphragm is a key factor in increasing gait speed in patients with hemiplegia. These findings may contribute to the development of trunk muscle strength-training programs that improve trunk function and gait speed in patients with hemiplegia.

Sounds of Silence in Times of COVID-19: Distress and Loss of Cardiac Coherence in People With Misophonia Caused by Real, Imagined or Evoked Triggering Sounds

The extreme, unprecedented situations in the current COVID-19 pandemic are risk factors for psychosocial stress for the entire population. However, strict confinement had a particular impact on people suffering from misophonia and their families. Misophonia is a condition in which hearing certain sounds triggers intense anger, disgust and even severe autonomic nervous system responses. This prospective cohort study examined the impact of strict confinement (Spain, March 14-June 21, 2020) on a sample of 24 people (16 women and eight men) who had been diagnosed with moderate to extreme misophonia and were regularly attending a medical psychology center in Barcelona. The 3-month period of confinement caused general emotional maladjustment, distress, and a transitory crisis. Long-term biomonitoring of their heart variability rate (HRV) enabled to identify a significant increase in physiological arousal after the confinement period, which had already been recorded in a loss of cardiac coherence under basal rest/relaxation conditions. Certain auditory stimuli triggered adverse responses, lowered HRV scores, and an increased stress level and heart rate. Loss of cardiac coherence in their responses to these auditory stimuli (triggering mouth, nose and other sounds), as well as to non-triggering mouth, nose and other sounds was increased when compared to two assessments performed during the previous year. Despite the limited sample size, sex differences were observed in the incidence. Loss of cardiac coherence worsened with the severity of the misophonia. Most importantly, imagined or evoked triggering sounds, as well as real ones, were enough to cause the aversive responses, as displayed by the increased loss of cardiac coherence with respect to the at-rest basal level. A semi-structured interview revealed the exceptional nature of the situations, increased hyper-sensorial sensitivity, fear of being infected with or dying from COVID-19, the patients' coping strategies, and the difficulties and constraints they faced. Finally, the article gives recommendations for better management of misophonia. Improved knowledge of this disorder would help address the current lack of health and social care, hopefully preventing this shortfall's impact on social and affective relationships, which are particulary important for well-being now and in the coming periods of physical distancing measures.

Effects of trunk lean and foot lift exercises in sitting position on abdominal muscle activity and the contribution rate of transversus abdominis

PURPOSE

Abdominal hollowing exercise has been recommended to improve trunk stability. Trunk lean and foot lift exercises while sitting may easily promote abdominal muscle activity even in people who cannot perform abdominal hollowing consciously. The purpose of the present study was to examine the changes in abdominal muscle activity and contribution rate of the transversus abdominis muscle (TrA) when leaning the trunk and lifting the foot during sitting.

METHODS

The muscle stiffnesses (indicators of muscle activity) of the right rectus abdominis, external oblique, internal oblique, and TrA of 14 healthy men were measured during abdominal hollowing and the following nine sitting tasks: reference posture, 15° and maximal posterior trunk lean, 20° and maximal ipsilateral and contralateral trunk lean, and ipsilateral and contralateral foot lift. The TrA contribution rate was calculated by dividing the TrA stiffness by the sum of the abdominal muscles' stiffnesses.

RESULTS

The TrA stiffness was significantly higher in abdominal hollowing than in reference posture, posterior and ipsilateral trunk lean, and ipsilateral foot lift, but not higher than in contralateral trunk lean and contralateral foot lift. There was no significant difference in the TrA contribution rates between abdominal hollowing and ipsilateral or contralateral foot lift.

CONCLUSION

The contralateral trunk lean or contralateral foot lift could enhance TrA activity for people who cannot perform abdominal hollowing consciously. The contralateral foot lift could particularly be beneficial to obtain selective activity of TrA.

Reciprocal relationship between multifidus and psoas at L4-L5 level in women with low back pain

Background Low back pain (LBP) may originate from different sources such as intervertebral disc degeneration (IVDD), end-plate and paraspinal muscle changes. Our aim is to explore the relevance of paraspinal muscles' fat-infiltration in women with LBP and its association with IVDD and Modic changes.Methods Consecutive female patients presenting with chronic LBP to the outpatient clinics were included. Patients were evaluated in terms of IVDD, vertebral end-plate changes, and fatty infiltration in the paraspinal muscles at all lumbar levels on lumbar spine magnetic resonance imaging (MRI). Visual Analogue Scale (VAS) scores were recorded using our prospectively collected database.Results Patients with higher VAS scores were significantly more likely to have more fatty infiltration in the multifidus and less fatty infiltration in the psoas at L4-L5 level when compared to those with lower VAS scores (69.1 vs. 31.8%, p = 0.003). To predict LBP, fatty infiltration in the multifidus and psoas had odds ratio (OR) of 4 (p = 0.010), and 0.3 (p = 0.013), respectively; whereas disc degeneration had an OR of 0.5 (p = 0.028).Conclusion This is the first clinical cross-sectional study suggested that women with chronic low back pain could have less fat-infiltrated psoas to compensate more fat-infiltrated multifidus at L4-L5 disc level.

Decreased respiratory-related postural perturbations at the cervical level under cognitive load

PURPOSE

In healthy humans, postural and respiratory dynamics are intimately linked and a breathing-related postural perturbation is evident in joint kinematics. A cognitive dual-task paradigm that is known to induce both postural and ventilatory disturbances can be used to modulate this multijoint posturo-ventilatory (PV) interaction, particularly in the cervical spine, which supports the head. The objective of this study was to assess this modulation.

METHODS

With the use of optoelectronic sensors, the breathing profile, articular joint motions of the cervical spine, hip, knees and ankles, and centre of pressure (CoP) displacement were measured in 20 healthy subjects (37 years old [29; 49], 10 females) during natural breathing (NB), a cognitive dual task (COG), and eyes-closed and increased-tidal-volume conditions. The PV interaction in the CoP and joint motions were evaluated by calculating the respiratory emergence (REm).

RESULTS

Only the COG condition induced a decrease in the cervical REm (NB: 17.2% [7.8; 37.2]; COG: 4.2% [1.8; 10.0] p = 0.0020) concurrent with no changes in the cervical motion. The CoP REm (NB: 6.2% [3.8; 10.3]; COG: 12.9% [5.8; 20.7] p = 0.0696) and breathing frequency (NB: 16.6 min-1 [13.3; 18.7]; COG: 18.6 min-1 [16.3; 19.4] p = 0.0731) tended to increase, while the CoP (p = 0.0072) and lower joint motion displacements (p < 0.05) increased.

CONCLUSION

This study shows stable cervical spine motion during a cognitive dual task, as well as increased postural perturbations globally and in other joints. The concurrent reduction in the PV interaction at the cervical spine suggests that this "stabilization strategy" is centrally controlled and is achieved by a reduction in the breathing-related postural perturbations at this level. Whether this strategy is a goal for maintaining balance remains to be studied.

Are respiratory disorders risk factors for troublesome low-back pain? A study of a general population cohort in Sweden

PURPOSE

A multi-morbidity perspective of troublesome low back pain (LBP) has been highlighted for example in relation to respiratory disorders. Our purpose was to investigate whether respiratory disorders are risk factors for reporting troublesome LBP in people with no or occasional LBP at baseline.

METHODS

This prospective cohort study was based on the Stockholm Public Health Cohort 2006/2010. We included adults reporting no or occasional LBP the last 6 months at baseline (n = 17,177). Exposures were self-reported asthma and/or Chronic Obstructive Pulmonary Disease (COPD). Outcome was troublesome LBP defined as reporting LBP a couple of days per week or more often that restricted work capacity or hindered daily activities to some or to a high degree, the last 6 months. Binomial regression models were used to calculate risk ratios (RR) with 95% confidence intervals (95% CI).

RESULTS

Adjusted results indicate that those suffering from asthma had a risk of troublesome LBP at follow-up (RR 1.29, 95% CI 0.92-1.81) as do those suffering from COPD (RR 2.0, 95% CI 1.13-3.56). If suffering from asthma and concurrent COPD the RR was 3.55 (95% CI 1.58-7.98).

CONCLUSION

Our findings indicate that suffering from asthma and/or COPD increases the risk of developing troublesome LBP, which highlights the importance to consider the overall health of people at risk of troublesome LBP and to take the multi-morbidity perspective into consideration. Future longitudinal studies are needed to confirm our findings. These slides can be retrieved under Electronic Supplementary Material.

Motor Control Changes in Low Back Pain: Divergence in Presentations and Mechanisms

Compared to healthy individuals, patients with low back pain demonstrate differences in all aspects of trunk motor control that are most often studied as differences in muscle activity and kinematics. However, differences in these aspects of motor control are largely inconsistent. We propose that this may reflect the existence of 2 phenotypes or possibly the ends of a spectrum, with "tight control" over trunk movement at one end and "loose control" at the other. Both may have beneficial effects, with tight control protecting against large tissue strains from uncontrolled movement and loose control protecting against high muscle forces and resulting spinal compression. Both may also have long-term negative consequences. For example, whereas tight control may cause high compressive loading on the spine and sustained muscle activity, loose control may cause excessive tensile strains of tissues. Moreover, both phenotypes could be the result of either an adaptation process aimed at protecting the low back or direct interference of low back pain and related changes with trunk motor control. The existence of such phenotypes would suggest different motor control exercise interventions. Although some promising data supporting these phenotypes have been reported, it remains to be shown whether these phenotypes are valid, how treatment can be targeted to these phenotypes, and whether this targeting yields superior clinical outcomes. J Orthop Sports Phys Ther 2019;49(6):370-379. Epub 12 Jun 2018. doi:10.2519/jospt.2019.7917.

Determination of the relationship between core endurance and isokinetic muscle strength of elite athletes

Muscle strength and core endurance are both factors contributing to athletes’ performance and prevalence of injuries. There are no studies indicating the relationship between muscle strength around the shoulder and knee joints and core endurance. The aim of our study is to determine the relationship between core endurance and isokinetic muscle strength of knees and shoulders of elite athletes. Seventy-one elite athletes (weight lifting, boxing, taekwondo, biathlon, and ice skating) (age, 18.13±2.9 years) were included in the study. Isokinetic muscle strength of shoulder internal-external rotation and knee flexion-extension were determined by using an Isomed 2000 device. Core endurance of athletes was assessed using the Mcgill Core Endurance Tests. There was a relationship between the shoulder internal rotation and external rotation peak torque/body weight (PT/W) and all endurance tests except extension endurance tests. There was also a relationship between knee flexion PT/W and all core endurance tests. While there was a relationship between knee extension PT/W and extension endurance and the lateral bridge test, this relationship was not found with the flexor endurance test. These results indicate that the upper and lower extremity muscle strength and core endurance of athletes are related with each other and must be evaluated and trained as a whole with each other.

Trunk Muscle Training Augmented With Neuromuscular Electrical Stimulation Appears to Improve Function in Older Adults With Chronic Low Back Pain: A Randomized Preliminary Trial

OBJECTIVES

To assess the feasibility of a trial to evaluate a trunk muscle training program augmented with neuromuscular electrical stimulation (TMT+NMES) for the rehabilitation of older adults with chronic low back pain (LBP) and to preliminarily investigate whether TMT+NMES could improve physical function and pain compared with a passive control intervention.

MATERIALS AND METHODS

We conducted a single-blind, randomized feasibility trial. Patients aged 60 to 85 years were allocated to TMT+NMES (n=31) or a passive control intervention (n=33), consisting of passive treatments, that is, heat, ultrasound, and massage. Outcomes assessed 3- and 6-month postrandomization included Timed Up and Go Test, gait speed, pain, and LBP-related functional limitation.

RESULTS

Feasibility was established by acceptable adherence (≥80%) and attrition (<20%) rates for both interventions. Both groups had similar, clinically important reductions in pain of >2 points on a numeric pain rating scale during the course of the trial. But, only the TMT+NMES group had clinically important improvements in both performance-based and self-reported measures of function. In terms of the participants' global rating of functional improvement at 6 months, the TMT+NMES group improved by 73.9% and the passive control group improved by 56.7% compared with baseline. The between-group difference was 17.2% (95% confidence interval, 5.87-28.60) in favor of TMT+NMES.

DISCUSSION

It seems that a larger randomized trial investigating the efficacy of TMT+NMES for the purpose of improving physical function in older adults with chronic LBP is warranted.

Development of a 3D workspace shoulder assessment tool incorporating electromyography and an inertial measurement unit-a preliminary study

Traditional shoulder range of movement (ROM) measurement tools suffer from inaccuracy or from long experimental setup times. Recently, it has been demonstrated that relatively low-cost wearable inertial measurement unit (IMU) sensors can overcome many of the limitations of traditional motion tracking systems. The aim of this study is to develop and evaluate a single IMU combined with an electromyography (EMG) sensor to monitor the 3D reachable workspace with simultaneous measurement of deltoid muscle activity across the shoulder ROM. Six volunteer subjects with healthy shoulders and one participant with a ‘frozen’ shoulder were recruited to the study. Arm movement in 3D space was plotted in spherical coordinates while the relative EMG intensity of any arm position is presented graphically. The results showed that there was an average ROM surface area of 27291 ± 538 deg² among all six healthy individuals and a ROM surface area of 13571 ± 308 deg² for the subject with frozen shoulder. All three sections of the deltoid show greater EMG activity at higher elevation angles. Using such tools enables individuals, surgeons and physiotherapists to measure the maximum envelope of motion in conjunction with muscle activity in order to provide an objective assessment of shoulder performance in the voluntary 3D workspace.

Graphical abstract

Ultrasound Assessment of the Abdominal Muscles at Rest and During the ASLR Test Among Adolescents With Scoliosis

STUDY DESIGN

Observational study.

OBJECTIVE

Are there deviations in the thickness of abdominal muscles at rest in individuals with adolescent idiopathic scoliosis (AIS)? Are there deviations in abdominal muscular activity in people with AIS during the active straight leg raise (ASLR) test?

SUMMARY OF BACKGROUND DATA

Ultrasound imaging can be used to assess the lateral abdominal muscle. Some authors suggest that scoliosis develops through a weakness or improper functioning of the abdominal muscles that cannot provide adequate support to the spinal segments. However, the literature lacks studies on the functioning of the abdominal muscles in individuals with spinal deviations. This study focuses on the evaluation of the thickness of the external oblique (EO), internal oblique (IO), and transversus abdominalis (TrA) muscles of individuals with AIS.

MATERIALS AND METHODS

Seventy-one healthy adolescents and 71 patients with AIS, all aged 10-16 years, were studied. The thickness of the muscles at rest was measured at the end of normal exhalation in millimeters. Muscular activity during the ASLR test was measured in the final position, and the standards were normalized with the thickness produced at rest. Muscular activity during the ASLR test was represented as a percentage change in the muscle thickness.

RESULTS

The AIS group demonstrated a smaller resting thickness of all tested muscles of both sides (P<0.01). All the muscles on the right side of the body showed higher activity in the AIS group during the ASLR test (P<0.01).

CONCLUSIONS

Patients with AIS had thinner EO, IO, and TrA at rest in the supine position. During the ASLR test, the AIS patients displayed higher activity of the EO, IO, and TrA muscles on the right side.

Motor control exercises of the lumbar-pelvic region improve respiratory function in obese men. A pilot study

PURPOSE

Obese subjects have decreased pulmonary function. The hypothesis of our study was that poor coordination of the lumbar-pelvic musculature secondary to obesity may hinder the synergic activation of the respiratory muscles. The aim of the paper was to evaluate whether specific motor control exercises of the lumbar-pelvic musculature were able to improve respiratory function.

METHOD

Twenty obese male patients underwent a rehabilitation program including adapted physical activity and respiratory physiotherapy. Patients were randomly assigned to a Specific Motor Control Exercise Group (SG) and a Control Group (CG). SG followed a protocol according to the SMARTERehab concept aimed at improving posture, intra-abdominal pressure, rib cage mobility, and perception of correct muscle activation. CG performed an exercise training protocol to improve aerobic capacity and muscle strength.

RESULT

After intervention, both groups showed similar changes in body weight, fat, and fat-free mass. Respiratory function indexes improved in SG due to improved proprioception and coordination of the deep lumbar-pelvic muscles.

CONCLUSION

Our study provides preliminary evidence that breathing, postural control, and spinal stability are intertwined. Positive respiratory effects in obese men can be obtained by prescribing specific motor control exercises of the lumbar-pelvic muscles. Implications for rehabilitation Obese subjects present with decreased pulmonary function and postural changes. Poor coordination of the lumbar-pelvic muscles affects posture and the synergic activation of the respiratory muscles. Specific motor control exercises of the lumbar-pelvic musculature can improve respiratory function. Breathing and postural control are intertwined: positive respiratory effects can be obtained by enhancing motor control of the lumbar-pelvic muscles.

Correlation Between Abdominal Muscle Thickness and Maximal Expiratory Pressure

OBJECTIVES

The activity of abdominal muscles mainly produces high expiratory pressure. These include the rectus abdominis, external oblique, internal oblique, and transverse abdominis muscles. The purpose of this study was to determine whether maximal expiratory pressure is associated with each abdominal muscle thickness at rest.

METHODS

Thirty-nine healthy male volunteers (mean age ± SD, 20.7 ± 2.7 years) participated in the study. The thickness of the right rectus abdominis, external oblique, internal oblique, and transverse abdominis muscles was measured by B-mode sonography in the supine position. The maximal expiratory pressure was obtained with a spirometer in the sitting position. The correlations between each abdominal muscle thickness and maximal expiratory pressure were determined by the Pearson correlation coefficient.

RESULTS

The correlation coefficient between the rectus abdominis muscle and maximal expiratory pressure was 0.571 (P< .001). Correlation coefficients between the external oblique, internal oblique, and transverse abdominis muscles and maximal expiratory pressure were 0.297 (P = .066), 0.267 (P = .100), and 0.022 (P = .894), respectively.

CONCLUSIONS

Our results indicate that the rectus abdominis muscle thickness might be more highly correlated with expiratory pressure production than the external oblique, internal oblique, and transverse abdominis muscle thickness.

The relationship between incontinence, breathing disorders, gastrointestinal symptoms, and back pain in women: a longitudinal cohort study

OBJECTIVES

Recent studies suggest a relationship between incontinence, respiratory disorders, gastrointestinal (GI) symptoms, and back pain (BP). However, causality is difficult to infer. This longitudinal study aimed to determine whether the presence or development of one disorder increases risk for the development of another.

METHODS

Women from the Australian Longitudinal Study on Women's Health were divided into subgroups; those with no BP (n=7259), no incontinence (n=18,480), no breathing problems (including allergy) (n=15,096), and no GI symptoms (n=17,623). Each subgroup was analyzed to determine the relationship between the development of the absent condition and the presence or development of the other conditions. Factors with a previously identified relationship with BP were included in analysis.

RESULTS

Women with pre-existing and/or newly developed incontinence (prevalence ratios [PR]: 1.26 to 2.12) and breathing problems (PR: 1.38 to 2.11) had an increased risk for the development of BP, and women with pre-existing and newly developed BP were more likely to develop incontinence and breathing problems (PR: 1.18 to 2.44 and 1.53 to 2.62, respectively). The presence of GI symptoms was also identified as a risk factor for the development of these conditions.

DISCUSSION

This study provides evidence of a relationship between BP, incontinence, respiratory problems, and GI symptoms in which the presence of one symptom is associated with the development of another. This suggests that common factors may contribute to the development of symptoms across this range of conditions.

Coordination of breathing with nonrespiratory activities

Many articles in this section of Comprehensive Physiology are concerned with the development and function of a central pattern generator (CPG) for the control of breathing in vertebrate animals. The action of the respiratory CPG is extensively modified by cortical and other descending influences as well as by feedback from peripheral sensory systems. The central nervous system also incorporates other CPGs, which orchestrate a wide variety of discrete and repetitive, voluntary and involuntary movements. The coordination of breathing with these other activities requires interaction and coordination between the respiratory CPG and those governing the nonrespiratory activities. Most of these interactions are complex and poorly understood. They seem to involve both conventional synaptic crosstalk between groups of neurons and fluid identity of neurons as belonging to one CPG or another: neurons that normally participate in breathing may be temporarily borrowed or hijacked by a competing or interrupting activity. This review explores the control of breathing as it is influenced by many activities that are generally considered to be nonrespiratory. The mechanistic detail varies greatly among topics, reflecting the wide variety of pertinent experiments.

Breath control during a tiptoe task

Examination of naturally occurring respiration during postural challenges may increase our understanding of the factors linking respiration to lumbar segmental control. This study determined if the timing and magnitude of inhaled volume changes were related to mechanical events that challenge spinal stability during a tiptoe task. Thirty healthy individuals (15 male) had airflow recorded while they completed a tiptoe task which involved: moving onto tiptoe while reaching toward a hanging target (ascent); grasping and holding the target while maintaining the tiptoe position for 3 s (hold); and then returning to the start position (descent). The rate of airflow and amount of inhaled volume (normalized to vital capacity (%VC)) were identified at 13 different intervals spanning the ascent, hold and descent phase. Using repeated measures analysis of variance, significant main effects were identified for both rate of airflow (p < 0.001) and %VC (p < 0.001). Exploration of these main effects revealed that individuals tended to inspire and increase %VC during the ascent phase, hold their breath and maintain %VC during the hold phase when whole body balance is challenged, and exhale during the descent phase. These findings are congruent with theories suggesting that breath control is linked in predictable ways to potentially improve lumbar spine stiffness when presented with mechanical challenges during functional tasks.

'The core': understanding it, and retraining its dysfunction

"Core stability training" is popular in both the therapeutic and fitness industries but what is actually meant and understood by this concept? And does everyone need the same training approach? This paper examines the landscape of 'the core' and its control from both a clinical and research perspective. It attempts a comprehensive review of its healthy functional role and how this is commonly changed in people with spinal and pelvic girdle pain syndromes. The common clinically observable and palpable patterns of functional and structural change associated with 'problems with the core' have been relatively little described. This paper endeavors to do so, introducing a variant paradigm aimed at promoting the understanding and management of these altered patterns of 'core control'. Clinically, two basic subgroups emerge. In light of these, the predictable difficulties that each group finds in establishing the important fundamental elements of spino-pelvic 'core control' and how to best retrain these, are highlighted. The integrated model presented is applicable for practitioners re-educating movement in physiotherapy, rehabilitation, Pilates, Yoga or injury prevention within the fitness industry in general.

An investigation of abdominal muscle recruitment for sustained phonation in 25 healthy singers

OBJECTIVES

The purpose of this study was to investigate the baseline muscle thickness and recruitment patterns of the transversus abdominis muscle (TAM) and the internal oblique muscle (IOM) during semisupine phonation in a group of healthy performers.

STUDY DESIGN

This was a 2 × 3×2 within-group, repeated-measure study in which 25 professional vocalists--12 male and 13 female performed a series of sustained pitches in differing vocal qualities. Measurements were taken with ultrasound (Sonosite Micromaxx Ultrasound System) of the baseline thickness and % recruitment during voicing, of two deep abdominal muscles--TAM and the IOM. Correlations between TAM and IOM absolute change scores, TAM and IOM percentage change scores, and changes in muscle thickness (absolute and percentage) and age were examined using Spearman's correlations. Gender differences in the four types of change scores within each combination of pitch and quality were conducted with one-way analysis of variances. Differences in muscle thickness change 1) absolute scores and 2) percentage change in TAM and IOM, by pitch and quality (and their interactions) were analyzed using linear mixed models, using restricted maximum likelihood estimations, employing a Toeplitz variance-covariance matrix structure in SPSS (IBM, 2011). Post hoc analyses for independent variable group differences used Sidak's correction for multiple comparisons. Alpha level was set to 0.05.

RESULTS

In terms of absolute contractions (changes in the actual millimeter thickness of the muscle), the IOM was greater than the TAM. However in terms of percentage changes in muscles during phonation, the TAM was always greater than the IOM. The TAM as a percentage change was recruited preferentially and significantly in most vocal qualities tested. Although there were differences in muscle mass and recruitment patterns between genders, and males had thicker muscle mass at rest, differences due to muscle mass were not conclusive.

CONCLUSIONS

Overall this study supports the argument that the peri-abdominal muscles do indeed play a role in supporting the "performing" or athletic voice in healthy subjects, and will hopefully act as a database for further research in individuals with healthy and injured voices.

Diaphragm postural function analysis using magnetic resonance imaging

We present a postural analysis of diaphragm function using magnetic resonance imaging (MRI). The main aim of the study was to identify changes in diaphragm motion and shape when postural demands on the body were increased (loading applied to a distal part of the extended lower extremities against the flexion of the hips was used). Sixteen healthy subjects were compared with 17 subjects suffering from chronic low back pain and in whom structural spine disorders had been identified. Two sets of features were calculated from MRI recordings: dynamic parameters reflecting diaphragm action, and static parameters reflecting diaphragm anatomic characteristics. A statistical analysis showed that the diaphragm respiratory and postural changes were significantly slower, bigger in size and better balanced in the control group. When a load was applied to the lower limbs, the pathological subjects were mostly not able to maintain the respiratory diaphragm function, which was lowered significantly. Subjects from the control group showed more stable parameters of both respiratory and postural function. Our findings consistently affirmed worse muscle cooperation in the low back pain population subgroup. A clear relation with spinal findings and with low back pain remains undecided, but various findings in the literature were confirmed. The most important finding is the need to further address various mechanisms used by patients to compensate deep muscle insufficiency.

Trunk muscle activity while lifting objects of unexpected weight

OBJECTIVE

To determine trunk muscle activity when lifting an object of greater weight than expected, which may contribute to the development of low back pain.

DESIGN

Electromyographic evaluation of trunk muscle activity.

SETTING

University of Tsukuba, Spine laboratory.

PARTICIPANTS

Eleven healthy men with a mean age of 24 (SD 2) years.

INTERVENTIONS

Trunk muscle activity was measured when subjects lifted an object with their right arm in immediate response to a light stimulus. Surface and wire electrodes were used to measure the activity of the rectus abdominis, external oblique and erector spinae muscles, and the transversus abdominis and lumbar multifidus muscles, respectively. The lifting tests were performed in three different settings: lifting an expected 1-kg object, lifting an unexpected 4-kg object (erroneously expected to weigh 1 kg), and lifting an expected 4-kg object.

MAIN OUTCOME MEASURES

The muscle activity induced when subjects lifted objects of different weights was compared by calculating the root mean square (RMS) of muscle activity at rest and % maximum voluntary contraction.

RESULTS

When the subjects were aware of the weight of the object to be lifted, the activity of the external oblique, transversus abdominis, erector spinae and lumbar multifidus muscles increased immediately after lifting. When the subjects were not aware of the weight of the object to be lifted, the increase in muscle activity was delayed (P<0.05).

CONCLUSIONS

Trunk muscles may not be able to function appropriately when individuals lift an object that is much heavier than expected.

Changes in lateral abdominal muscle thickness during an abdominal drawing-in maneuver in individuals with and without low back pain

The purpose of this study was to compare lateral abdominal muscle thickness changes in individuals with and without low back pain (LBP) during an abdominal drawing-in maneuver (ADIM) using ultrasound imaging. Twenty individuals (13 females and 7 males, average age 40.1 ± 13.4) with stabilization classification LBP and 19 controls (10 females and 9 males, average age 30.3 ± 8.7) participated in this study. Bilateral measurements were made using ultrasound imaging to determine changes in thickness of the transversus abdominus (TrA) and external and internal oblique (EO+IO) muscles during an ADIM. There were no significant differences in relaxed muscle thickness values or contraction ratios for the TrA or EO+IO between groups or side. Individuals with stabilization classification LBP demonstrated no difference in lateral abdominal muscle thickness during an ADIM when compared with controls without LBP when using a pressure biofeedback device to monitor stability.

Individuals with low back pain breathe differently than healthy individuals during a lifting task

STUDY DESIGN

Case control, repeated-measures, experimental laboratory study.

OBJECTIVE

To determine if, during a whole-body lifting task, individuals with low back pain (LBP) breathe differently than age-matched controls.

BACKGROUND

Breath control may be optimized to provide increased intersegmental control of the lumbar spine through the generation of intra-abdominal pressure. Consequently, impairments in respiratory and trunk muscle coordination during lifting tasks may contribute to the occurrence or maintenance of LBP.

METHODS

Participants without LBP (n = 30) were matched by gender and age with those presenting with chronic mechanical LBP (n = 32) of at least 1 year in duration. Participants completed a total of 8 self-paced lifts of a crate from the floor to a table, with the crate empty during 4 of the lifts and loaded to 25% of the participant's body weight during 4 of the lifts. The amount of volume in the lungs, measured as a percentage of the individual's vital capacity (%VC), was identified at 9 points during the lifting task. A 2 × 2 × 2 × 9 (group by gender by load by time) mixed-model analysis of covariance (ANCOVA), with age as the covariate, was used to identify differences among conditions and groups of %VC used during the lift.

RESULTS

Individuals with LBP performed the lifting task with more volume in their lungs (48.2 %VC) than healthy peers (40.9 %VC). Age significantly affected %VC used during the lift: with increasing age, participants with LBP increased inspired volume and participants without LBP decreased inspired volume.

CONCLUSIONS

Individuals with LBP performed a lifting task with more inhaled lung volume than individuals without LBP. These findings are consistent with the theoretical link between breath control, intra-abdominal pressure, and lumbar segmental control.

An interdisciplinary pain rehabilitation programme: description and evaluation of outcomes

PURPOSE

The purpose of this archival report is to describe the essential elements of an intensive 8-week interdisciplinary pain rehabilitation programme (IPRP) with a cognitive-behavioural emphasis and the results that can be expected in treating patients with chronic pain conditions.

METHOD

This report describes a private outpatient program providing treatment services to patients with long-term disabling pain arising from work- or accident-related musculoskeletal injuries. The cohort consists of 338 consecutive patients who completed the program over a 3-year period (patients discharged between January 1, 2005, and December 31, 2007).

RESULTS

Improvements in vocational status were noted in 75% of patients with chronic pain. Patients were also able to reduce their pain levels by approximately 16% and to reduce their levels of anxiety and depression by 13% and 17% respectively. At the same time, 61% of patients were able to reduce or eliminate their pain medications.

CONCLUSIONS

Outcomes are consistent with evidence-based clinical practice guidelines for the management of chronic pain conditions. The published literature supports the efficacy of this interdisciplinary approach in highly disabled patients for whom effective treatment has been delayed. Early intervention in the subacute phase is recommended for prevention of long-term disability in patients with chronic pain.

The effect of experimental groin pain on abdominal muscle thickness

OBJECTIVES

It is not clear whether abnormal abdominal muscle behavior in athletes with longstanding groin pain is a risk factor for groin pain or is caused by groin pain itself. Therefore, this study investigated whether anticipation of experimental groin pain influences abdominal muscle behavior.

METHODS

In 14 healthy athletes, abdominal muscle thickness was measured using ultrasound under conditions of anticipated groin pain and acute groin pain. Groin pain was induced using superficial electrical skin stimulation. Tasks evaluated were isometric hip adduction and active straight leg raise (ASLR) left.

RESULTS

The m. transversus abdominis and m. obliquus internus showed a significant decrease in thickness during "anticipation of pain" compared with "no pain" and "pain" during both hip adduction and ASLR (P values <0.04). For m. obliquus externus, a significant increase in thickness was found only during "pain" compared with "no pain" and "anticipation of pain" for ASLR (P<0.004).

DISCUSSION

If ASLR or hip adduction is associated with anticipated groin pain, abdominal muscle behavior is different from a pain-free situation and from a painful situation. These results suggest that abnormal abdominal muscle behavior found in athletes with longstanding groin pain may be caused by a pain anticipatory motor strategy. This may have implications for rehabilitation.

The putative involvement of the transabdominal muscles in dysphonia: a preliminary study and thoughts

OBJECTIVES/HYPOTHESIS

Real-time ultrasound was used as an adjunct to assess patterns of periabdominal musculature in 14 individual with dysphonia and muscle tension dysphonia.

MATERIALS

Fourteen individuals with muscle tension dysphonia were evaluated with real-time ultrasound as a part of their initial evaluation and management.

RESULTS

In 13 of 14 individuals, there was an imbalance found during phonation between the transversus abdominis muscles (TAs) and internal oblique muscles (IOs), whereby the IOs were found to be overactive and the TAs underactive. After physiotherapy, this pattern was reversed.

CONCLUSION

The abdominal muscle pattern of overactivity of the internal oblique and underactivity of the TA during phonation was found to be present in the large majority of patients in this pilot sample who had presented with muscle tension dysphonia. The significance of this is unclear but deserves further review.

The effect of resisted inspiration during an active straight leg raise in pain-free subjects

Alterations of respiratory patterns have been observed in pelvic girdle pain subjects during the active straight leg raise (ASLR). This study investigated how pain-free subjects coordinate motor control during an ASLR when this task is complicated by the addition of a respiratory challenge. Trunk muscle activation, intra-abdominal pressure, intra-thoracic pressure, pelvic floor motion, downward pressure of the non-lifted leg and respiratory rate were compared between resting supine, ASLR, breathing with inspiratory resistance (IR) and ASLR+IR. Subjects responded to ASLR+IR with an increase in the motor activation in the abdominal wall and chest wall compared to when ASLR and IR were performed in isolation. Activation of obliquus internus abdominis was greater on the side of the leg lift during the ASLR+IR, in comparison to symmetrical activation observed in the other abdominal wall muscles. The incremental increase of motor activity was associated with greater intra-abdominal pressure baseline shift when lifting the leg during ASLR+IR compared to ASLR. Individual variation was apparent in the form of the motor control patterns, mostly reflected in variable respiratory activation of the abdominal wall. The findings highlight the flexibility of the neuromuscular system in adapting to simultaneous respiratory and stability demands.

Driving plasticity in the motor cortex in recurrent low back pain

The sensory and motor systems can reorganise following injury and learning of new motor skills. Recently we observed adaptive changes in motor cortical organisation in patients with recurrent low back pain (LBP), which are linked to altered motor coordination. Although changes in motor coordination can be trained and are associated with improved symptoms and function, it remains unclear whether these training-induced changes are related to reorganisation of the motor cortex. This was investigated using the model of a delay in postural activation of the deep abdominal muscle, transversus abdominis (TrA) in 20 individuals with recurrent LBP. Subjects were allocated to either motor skill training that involved isolated voluntary contractions of TrA, or a control intervention of self-paced walking exercise for 2 weeks. Electromyographic (EMG) activity was recorded from TrA bilaterally using intramuscular fine-wire electrodes. Motor cortical organisation using transcranial magnetic stimulation (TMS) and postural activation associated with single rapid arm movements were investigated before and after training. Motor skill training induced an anterior and medial shift in motor cortical representation of TrA, towards that observed in healthy individuals from our previous study. This shift was associated with earlier postural activation of TrA. Changes were not observed following unskilled walking exercise. This is the first observation that motor training can reverse reorganisation of neuronal networks of the motor cortex in people with recurrent pain. The observed relationship between cortical reorganisation and changes in motor coordination following motor training provides unique insight into potential mechanisms that underlie recovery.

Resting thickness of transversus abdominis is decreased in athletes with longstanding adduction-related groin pain

The purpose of the study was to compare thickness of the transversus abdominis (TA) and obliquus internus (OI) muscles between athletes with and without longstanding adduction-related groin pain (LAGP). Forty two athletes with LAGP and 23 controls were included. Thickness of TA and OI were measured with ultrasound imaging on the right side of the body during rest. Relative muscle thickness (compared to rest) was measured during the active straight leg raise (ASLR) left and right, and during isometric hip adduction. TA resting thickness was significantly smaller in injured subjects with left-sided (4.0+/-0.82mm; P<0.001) or right-sided (4.3+/-0.64mm; P=0.015) groin complaints compared with controls (4.9+/-0.90mm). No significant differences between patients and controls in TA or OI relative thickness during the ASLR and isometric hip adduction were found (all cases P>/=0.15). In conclusion, TA resting thickness is smaller in athletes with LAGP and may thus be a risk factor for (recurrent) groin injury. This may have implications for therapy and prevention of LAGP.

No relation between pelvic belt tests and abdominal muscle thickness behavior in athletes with long-standing groin pain. Measurements with ultrasound

OBJECTIVE

To investigate whether abdominal muscle thickness in athletes with long-standing adduction-related groin pain (LAGP) differs between subgroups with a positive or no response to a pelvic belt. The response to a pelvic belt is defined positive in case of a decrease > or = 1 on a Likert pain scale (0-10) during the squeeze test (SQT) or a decrease > or = 1 on the active straight leg raise (ASLR) test score (0-10).

DESIGN

Cross-sectional study.

SETTING

Physical therapy practice.

PATIENTS

Fifty athletes with LAGP.

INDEPENDENT VARIABLES

Squeeze test and ASLR test.

MAIN OUTCOME MEASURES

First, the effect of a pelvic belt on pain during the SQT and the ASLR test score was evaluated. Then, thickness of m. transversus abdominis (TA) and m. obliquus internus (OI) was measured using ultrasound during rest, ASLR left and right, and SQT.

RESULTS

Of the 50 participants, 25 (50%) experienced a decrease in pain during the SQT when wearing a pelvic belt and 10 (20%) improved in ASLR performance with a pelvic belt. Thickness of TA and OI at rest (both cases P > .08) and relative thickness compared with rest during tasks (in all cases P > .12) revealed no significant difference when comparing the 2 subgroups based on the belt response during the SQT or ASLR.

CONCLUSIONS

Using these methods, abdominal muscle thickness behavior in athletes with LAGP did not differ between the subgroups based on a positive or no response to a pelvic belt. However, the ultrasound method used may not have been sensitive enough to reveal differences between groups.

Transversus abdominis: changes in thickness during the unsupported upper limb exercise test in older adults

Novel, short-lived upper limb tasks performed by young adults have been used to investigate the role of transversus abdominis (TrA) in maintaining postural stability. Little information exists concerning the behaviour of TrA in older adults during protracted postural challenges. The primary aim of this study was to describe the change in thickness of TrA during an incremental upper limb exercise test in older adults. A secondary analysis was undertaken to compare the results between younger and older subjects. Healthy subjects aged between 40 and 70 years performed the Unsupported Upper Limb Exercise Test (UULEX) while activity of TrA was continuously monitored by using rehabilitative ultrasound imaging. Changes in muscle dimensions were measured every minute during the test. The thickness of TrA increased significantly and exponentially between minutes 8 and 13 of the UULEX. Although there was a significant difference between older and younger subjects in absolute measures of TrA thickness, the change in TrA thickness as a percentage of resting thickness during the UULEX demonstrated an identical pattern between younger and older subjects. This study suggests that TrA is continually and increasingly active during an upper limb task in both younger and older asymptomatic subjects.

Orthopaedic manifestations of congenital myotonic dystrophy during childhood and adolescence

BACKGROUND

Congenital myotonic dystrophy (CMD) is a dominantly inherited disorder manifested in childhood by muscle weakness which can be profound at birth, but which progressively improves over the first few years. Congenital myotonic dystrophy represents the severe end of the spectrum of myotonic dystrophy, which in milder cases may not be diagnosed until adulthood. The goal of the study was to identify and quantitate the musculoskeletal deformities which may significantly affect the function of children with CMD.

METHODS

A retrospective chart and radiograph review was performed after Institutional Review Board approval for all cases of myotonic dystrophy from 1987 to 2004 followed at a children's specialty orthopaedic hospital. Inclusion criteria were either a conclusive testing for CMD by gene testing, electromyography, and/or muscle biopsy in the child or parent and the presence of a typical clinical picture. Skeletal manifestations were classified by body segment (upper extremity, hand, spine, hip, lower extremity, foot) and by the type of deformity. Surgical procedures and outcomes were also documented.

RESULTS

Thirty children and adolescents met the inclusion criteria. The male/female ratio was 1 (15 boys and 15 girls). In 27 cases, the mother transmitted the disease, and in 2 cases, the father transmitted the disease; in one case, it was impossible to reconstitute the family history of the child who was adopted. The mean age at onset of gait was 29 months. Twenty-two (73%) out of 30 children underwent surgery for lower extremity-, foot-, or spinal-related deformities. The mean follow-up was 11.4 years (range, 3-20 years).No contractures or deformities were observed in the upper extremities. Spinal deformities affected 9 patients (30%), and 3 of these required surgery. These spinal deformities when present usually had an early onset and included thoracolumbar scoliosis as well as kyphoscoliosis. Problems at the level of the hips and knee were infrequent and included only 2 patients who had unilateral hip abduction contracture and 1 patient who had significant fixed knee flexion contracture. Congenital clubfoot occurred in 5 patients (17%) and generally responded well after posteromedial release and recurrence occurred in only one case. Developmental equinus and equinovarus exclusive of clubfoot affected 7 patients (23%), 70% of whom required surgery. Outcome after Achilles tendon lengthening was positive, and many of the children began walking soon after the Achilles lengthening, and recurrence did not occur.

CONCLUSIONS

Child with CMD are at high risk for musculoskeletal deformities of the spine and lower extremities. In our experience, correction and improved function were likely after surgery.

LEVEL OF EVIDENCE

Retrospective study; level IV.

Links between the mechanics of ventilation and spine stability

Spine stability is ensured through isometric coactivation of the torso muscles; however, these same muscles are used cyclically to assist ventilation. Our objective was to investigate this apparent paradoxical role (isometric contraction for stability or rhythmic contraction for ventilation) of some selected torso muscles that are involved in both ventilation and support of the spine. Eight, asymptomatic, male subjects provided data on low back moments, motion, muscle activation, and hand force. These data were input to an anatomically detailed, biologically driven model from which spine load and a lumbar spine stability index was obtained. Results revealed that subjects entrained their torso stabilization muscles to breathe during demanding ventilation tasks. Increases in lung volume and back extensor muscle activation coincided with increases in spine stability, whereas declines in spine stability were observed during periods of low lung inflation volume and simultaneously low levels of torso muscle activation. As a case study, aberrant ventilation motor patterns (poor muscle entrainment), seen in one subject, compromised spine stability. Those interested in rehabilitation of patients with lung compromise and concomitant back troubles would be assisted with knowledge of the mechanical links between ventilation during tasks that impose spine loading.

A new method for the noninvasive determination of abdominal muscle feedforward activity based on tissue velocity information from tissue Doppler imaging

Rapid arm movements elicit anticipatory activation of the deep-lying abdominal muscles; this appears modified in back pain, but the invasive technique used for its assessment [fine-wire electromyography (EMG)] has precluded its widespread investigation. We examined whether tissue-velocity changes recorded with ultrasound (M-mode) tissue Doppler imaging (TDI) provided a viable noninvasive alternative. Fourteen healthy subjects rapidly flexed, extended, and abducted the shoulder; recordings were made of medial deltoid (MD) surface EMG and of fine-wire EMG and TDI tissue-velocity changes of the contralateral transversus abdominis, obliquus internus, and obliquus externus. Muscle onsets were determined by blinded visual analysis of EMG and TDI data. TDI could not distinguish between the relative activation of the three muscles, so in subsequent analyses only the onset of the earliest abdominal muscle activity was used. The latter occurred <50 ms after the onset of medial deltoid EMG (i.e., was feedforward) and correlated with the corresponding EMG onsets (r = 0.47, P < 0.0001). The mean difference between methods was 20 ms and was likely explained by electromechanical delay; limits of agreement were wide (-40 to +80 ms) but no greater than those typical of repeated measurements using either technique. The between-day standard error of measurement of the TDI onsets (examined in 16 further subjects) was 16 ms. TDI yielded reliable and valid measures of the earliest onset of feedforward activity within the anterolateral abdominal muscle group. The method can be used to assess muscle dysfunction in large groups of back-pain patients and may also be suitable for the noninvasive analysis of other deep-lying or small/thin muscles.

Observed changes in lateral abdominal muscle thickness after spinal manipulation: a case series using rehabilitative ultrasound imaging

STUDY DESIGN

Case series.

BACKGROUND

A clinical prediction rule (CPR) has been developed and validated that accurately identifies a subgroup of patients with low back pain (LBP) likely to benefit from spinal manipulation; however, the mechanism of spinal manipulation remains unclear. The purpose of this case series was to describe changes in lateral abdominal muscle thickness using rehabilitative ultrasound imaging (RUSI) immediately following spinal manipulation in a subgroup of patients positive on the rule.

CASE DESCRIPTIONS

Data from 9 patients (5 female, 4 male; 18-53 years of age) with a primary complaint of LBP are presented. All patients had symptoms for less than 16 days (range, 3-14 days) and did not have symptoms distal to the knee, satisfying the 2-factor rule for predicting successful outcome from spinal manipulation. The Oswestry Disability Index scores ranged from 8% to 52%. Lateral abdominal muscle thickness was assessed with the patient at-rest and while contracted during an abdominal drawing-in maneuver (ADIM) using RUSI. Measurements were taken before and immediately after spinal manipulation. Patients completed a 15-minute training session of the ADIM prior to assessment, to mitigate the potential for a learning effect to occur.

OUTCOMES

Based on changes that exceeded the threshold for measurement error, 6 of 9 patients demonstrated an improved ability (11.5%-27.9%) to increase transversus abdominis (TrA) muscle thickness during the ADIM postmanipulation. Additionally, TrA muscle thickness at-rest postmanipulation decreased for 5 patients (11.5%-25.9%), while at-rest internal oblique muscle thickness decreased for 4 patients (6.4%-12.2%).

DISCUSSION

This case series describes short-term changes in lateral abdominal muscle thickness post spinal manipulation. Although case series have significant limitations, including the fact that no cause-and-effect claims can be made, the decrease in muscle thickness at rest and the greater increase in muscle thickness during the ADIM postmanipulation observed in some of the patients could suggest an improvement in muscular function. Future research is needed to determine if increased muscle thickness is associated with improvements in pain and disability and to further explore neurophysiologic mechanisms of spinal manipulation.