Background. Previous work has identified differential kinematics and muscle activity between non-specific chronic low back pain (LBP) subgroups (flexion pattern (FP) and active extension pattern) and healthy controls. However, it is unclear if differences in muscle activity are maintained on resolution of pain and/or if they contribute to pain recurrence. Purpose. To investigate differences in trunk muscle activity between individuals with a history of flexion-related LBP (who are currently pain-free) and no-LBP controls during three functional activities. Methods. Fifteen individuals (10 male, 5 female) with a previous history of FP LBP (but who were currently pain-free) and 15 individuals with no history of low back pain (10 male, 5 female) were recruited. Surface electromyography of bilateral superficial lumbar multifidus, longissimus thoracis, transversus abdominus/internal oblique and external oblique muscle activity was recorded during three functional activities (sit-to-stand, step-up and bending to pick up a pen from the floor). Surface electromyography data was normalised (% maximum voluntary contraction) and compared between groups (Mann-Whitney U test). Results. No significant differences were observed for any muscle in any activity (p>0.05) except for significantly increased right superficial lumbar multifidus during the bending task (p=0.04) in the FP group compared to the control group (36.55 vs. 19.97 respectively). Conclusion. Individuals with resolved FP LBP have similar trunk muscle activation to those with no history of LBP. This suggests that muscle activity behaviours may ‘normalise’ in FP on resolution of pain. Further work should explore muscle activity during recurrent episodes to establish links with pain provocation. No conflicts of interest. No funding obtained

Background. Trunk muscle activity and thoraco-lumbar kinematics have been shown to discriminate non-specific chronic low back pain (NSCLBP) subgroups from healthy controls. Thoracic spine kinematics and muscle activity whilst intuitively associated with NSCLBP, has received less attention and the possibility of intra-regional interactions remains an area for exploration. Purpose. Determine relationships between muscle activation and kinematics in active extension pattern (AEP) and flexion pattern (FP) subgroups and no-low back pain controls during a sagittal bending task. Methods. Fifty NSCLBP subjects (27 FP, 23 AEP) and 28 healthy controls underwent 3D motion analysis (Vicon™) and surface electromyography whilst bending to retrieve a pen from the floor. Mean sagittal angle for the upper and lower thoracic and lumbar regions (UTx, LTx, ULx, LLx) were compared with normalised mean amplitude electromyography of 4 bilateral trunk muscles. Pearson correlations were computed to assess relationships. Results. Significant relationships between lumbar multifidus and ULx/LLx were identified in AEP during bending and return (p<0.01). FP exhibited multiple significant interactions including between longissimus thoracis and lumbar multifidus and LLx/LTx (p<0.035); and external oblique activity and UTx/LTx (p<0.05) during bending and return (and LLx during bending). Correlations were moderate to strong (r= −0.812 to 0.664). Conclusion. Kinematic and trunk muscle activity measurements differentiated between NSCLBP sub-groups and controls, especially between LLx kinematics and lumbar multifidus activity. Contrasting muscle activation patterns between LLx and LTx regions in FP highlights the importance of regional thoracic measurements, and suggests likely compensation strategies. Replication during other tasks should be evaluated in future studies. No conflicts of interest. Funding provided by Versus Arthritis (Formerly Arthritis Research UK)

Purpose & Background. The ability to jump higher is a key factor for athletic performance and relies on many factors including spinal movement and trunk muscle activity. Manual therapy including Mulligan' Sustained Natural Apophyseal Glide (SNAG) techniques are proposed to increase spinal movement and thus function. The evidence pf the effect of manual therapy on muscle activity is limited. We aimed to determine the immediate effects of an extension SNAG on the lower lumbar spine on jump height and rectus abdominis (RA), external oblique (EO), multifidus (M) and iliocostalis Lumborum (IL) muscle activity during the flight phase of vertical jump compared to a placebo intervention (flat hand pressure). Method. Eighteen healthy participants (16 males, age 28.11±5.01 years, weight 70.58±11.9 kg, height 1.70±0.07m, body mass index 24.28±3.30)from Cardiff University were randomly allocated to either an extension SNAG or placebo intervention. Surface Electromyography was normalised to maximum voluntary contraction and was collected during the flight phase of the jump and jump height was measured using jump and reach test. Results. There was a significant increase (p=0.01) in jump height for the SNAG group. No significant differences in RA, EO, M, IL muscle activity was noted between SNAG and placebo interventions In EO, LES and M descriptive analysis showed a decrease in muscle activity in on average 14 of the subjects. Conclusion. SNAG mobilisation can produce an immediate increase in jump height but no significant changes in muscle activity in healthy subjects. Further work is warranted in subjects with low back pain. No Conflict of Interests. No funding was obtained

Aims

The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique.

Purposes of the study and background. Characteristics of muscle activity, represented by surface electromyography (EMG), have shown differences between patients with low back pain and healthy adults; how they relate to functional/clinical scales remains unclear. The purpose of the current study was to examine the correlation between frequency characteristics of EMG and patients' self-rated score of disability using continuous wavelet transform (CWT) analysis. Methods and Results. Fifteen patients with chronic mechanical low back pain (LBP) and 10 healthy adults were recruited. Patients completed the Roland-Morris Disability Questionnaire (RMDQ) and bilateral EMG activity was obtained from erector spinae at vertebral level L4 and T12. Subjects performed 3 brief maximal voluntary contractions (MVCs) of the back extensors and the torque was measured using a dynamometer. CWT was applied to the EMG signals of each muscle in a 200ms window centred around the peak torque obtained during the MVCs. The ratio (low/high frequencies) of the energy, the peak energy, and the frequency of the peak energy were calculated for each muscle and then averaged and correlated with the individual's RMDQ score. Patients had significantly lower peak power than the controls (p=0.04). Additionally, RMDQ positively correlated to the average ratio of energy (rho=0.71; p=0.01), meaning higher disability corresponded to a dominant distribution of energy in the lower-frequencies; but negatively correlated to the average frequency of peak energy (rho=-0.61; p=0.035), meaning lower frequency of peak energy corresponded to higher levels of disability. Conclusion. The current findings support anatomical evidence of changes in muscle fibre composition of back muscles in subjects with chronic LBP. Conflicts of interest: No conflicts of interest. Sources of funding: No funding obtained

Statement of Purpose. It is well known that individuals with a history of low back pain (hLBP) exhibit altered movement patterns that are caused by changes in neuromuscular control. Postural disturbance provides an effective method for creating these differentiable movement patterns. This study has explored the response of the lower limb and spine to a translational perturbation similar to that experienced on public transport in healthy volunteers and those with hLBP. Methods. Healthy volunteers (n=16) and subjects with hLBP (n=10) were subjected to 31 identical postural disturbances at varying time intervals while standing atop a moving platform. Skeletal kinematics and muscle activation were recorded using a 10-camera Vicon system (Oxford, UK) and Myon electromyography (EMG) at the trunk (lumbar, lower thoracic, and upper thoracic segments), pelvis, thigh, calf, and foot. Joint angles were calculated using Body Builder (Vicon) and a unilateral seven-segment custom model. Results. Examination of the total range of joint motion (RoM) exhibited during the trial demonstrated similar RoM at the knee and hip (p=0.90 and 0.97 respectively), but less RoM for the hLBP group at the ankle and lumbar spine (p=0.21 and 0.38, respectively). EMG signals revealed higher muscle activation of the lower limbs from the hLBP cohort compared to healthy controls, yet greater activation at the gluteal and oblique muscles in the control group. Conclusions. In the presently small cohorts, trends demonstrate that differences in postural strategies exist between the healthy and hLBP cohorts, yet further testing of LBP patients will further clarify targets for rehabilitation

Purpose. To determine the effect of leg dominance on trunk muscle activity during bridging exercises on the floor and a gym ball. Background. Perturbation training including bridging exercises and unstable surfaces have been shown to increase trunk activity. Trunk muscle activity increases on the contralateral side to the stabilising leg during bridging, however, no studies exist on the effect of leg dominance on trunk muscle activity during bridging exercises. This study will investigate whether trunk muscle activity differs when stabilising on the dominant versus non-dominant leg. Method. A same subject observational design collected surface electromyography (SEMG) muscle activity for right (R) and left (L) bilateral IO and EO in 2 bridging exercises. (1) feet on the floor, (2) legs on a gym ball. 13 subjects, all right leg dominant (age, 21.53±1.50 years, height 169.38±8.33 centimetres, weight 67.91±10.60 kilograms gave informed consent. All SEMG data was normalized against maximum voluntary contractions. Data was analysed using paired t-test or Wilcoxon rank analysis. Results. In the ball exercise lifting the dominant leg significantly increased RIO (p=0.004), in the floor exercise lifting the dominant leg significantly increased LEO (p=0.03) and RIO (p=0.05). In the ball exercise lifting the non-dominant leg significantly increased LIO p=(0.007) and LEO (p=0016). All other recordings were non-significant. Conclusion. There was no consistency in increase in trunk muscle activity when comparing lifting the dominant and non dominant leg in the two exercise conditions. This may reflect the variability in individual trunk muscle response to perturbations

Introduction. Previous work(. 1. ) has suggested that Spectral Colour Mapping (SCM) may have potential as an objective measurement tool for analysing Electromyography (EMG) data from spinal muscles, but the production and analysis of these maps is a complex undertaking. It would be beneficial for a system to create these maps and be useable with a minimum of training. Methods. EMG data was recorded from 192 subjects across two years (initial contact, 12 months and 24 months). The data were analysed and SCMs produced. The 30 second test data was split into 30 one second epochs. Colour values were scaled to the individual data set maximum and divided into 12 bands according to frequency strength at a particular point. Median Frequency values were calculated for each epoch and a line of best fit added to the colour map to further aid the diagnosis process. Maps with faulty recordings were excluded and 20 data sets from each group (BP and no BP) selected at random. Four observers were given only 5 minutes instruction and then asked to indicate whether they thought each map belonged to the LBP or no LBP group. Results. The results ranged from an accuracy of 72.5%, down to 40%. These figures were closely correlated to the experience level of the observer in question. This would suggest that improving and extending the instruction period would improve these outcomes. This test is to be repeated in two months after the observers have completed additional training, the results will be demonstrated at the meeting

Staying active, including walking is promoted as being beneficial for patients with low back pain (LBP). The abdominal muscles appear to influence the stability of the spine and their activity has been shown to change when patients have LBP. Walking with Nordic walking poles has been shown to influence forces on the lower limbs, but little research has investigated the effect on the trunk muscles. Aim: to study the effect of walking using Nordic walking poles on abdominal muscle activity and lower limb forces. Method 15 healthy subjects gave informed consent (5 males. 10 females, age 21.06 yrs.(±88), height 174.45cms (±11.1), weight 71.44 kg (±15.2)). Following a period of walking training with Nordic walking poles data was obtained during a period of walking for internal IO) and external oblique (EO) using surface electromyography activity and vertical lower limb forces (Newtons, (N)) with (WP) and without Nordic walking poles (NP). SEMG data was normalised to maximum voluntary contraction. Results. There were significant increases in IO (p=0.02, NP 31.94 (±39.9) WP 53.05 (±40.61)), EO (p=0.02, NP 46.45, (±30.9), WP 87.93 ± (±60.5)) and vertical forces with poles (p=0.008, NP871.6 (±237.00)N, WP 968.33, (±210.8) N). Discussion. Using Nordic walking poles significantly increases activity of IO and EO, which may be of value in the rehabilitation of some patients with LBP. Vertical forces increased when walking with poles which is contrary to previous research. This may be due to the data collection setting of a research laboratory or the subjects being novice walkers

Aims

To report the surgical outcome of patients with severe Scheuermann’s kyphosis treated using a consistent technique and perioperative management.

The aim of this study was to evaluate the feasibility of using the intact S1 nerve root as a donor nerve to repair an avulsion of the contralateral lumbosacral plexus. Two cohorts of patients were recruited. In cohort 1, the L4–S4 nerve roots of 15 patients with a unilateral fracture of the sacrum and sacral nerve injury were stimulated during surgery to establish the precise functional distribution of the S1 nerve root and its proportional contribution to individual muscles. In cohort 2, the contralateral uninjured S1 nerve root of six patients with a unilateral lumbosacral plexus avulsion was transected extradurally and used with a 25 cm segment of the common peroneal nerve from the injured leg to reconstruct the avulsed plexus.

The results from cohort 1 showed that the innervation of S1 in each muscle can be compensated for by L4, L5, S2 and S3. Numbness in the toes and a reduction in strength were found after surgery in cohort 2, but these symptoms gradually disappeared and strength recovered. The results of electrophysiological studies of the donor limb were generally normal.

Severing the S1 nerve root does not appear to damage the healthy limb as far as clinical assessment and electrophysiological testing can determine. Consequently, the S1 nerve can be considered to be a suitable donor nerve for reconstruction of an avulsed contralateral lumbosacral plexus.

Cite this article: Bone Joint J 2015; 97-B:358–65.

The widespread use of MRI has revolutionised the diagnostic process for spinal disorders. A typical protocol for spinal MRI includes T1 and T2 weighted sequences in both axial and sagittal planes. While such an imaging protocol is appropriate to detect pathological processes in the vast majority of patients, a number of additional sequences and advanced techniques are emerging. The purpose of the article is to discuss both established techniques that are gaining popularity in the field of spinal imaging and to introduce some of the more novel ‘advanced’ MRI sequences with examples to highlight their potential uses.

Cite this article: Bone Joint J 2015;97-B:1683–92.

C5 nerve root palsy is a rare and potentially debilitating complication of cervical spine surgery. Currently, however, there are no guidelines to help surgeons to prevent or treat this complication.

We carried out a systematic review of the literature to identify the causes of this complication and options for its prevention and treatment. Searches of PubMed, Embase and Medline yielded 60 articles for inclusion, most of which addressed C5 palsy as a complication of surgery. Although many possible causes were given, most authors supported posterior migration of the spinal cord with tethering of the nerve root as being the most likely.

Early detection and prevention of a C5 nerve root palsy using neurophysiological monitoring and variations in surgical technique show promise by allowing surgeons to minimise or prevent the incidence of C5 palsy. Conservative treatment is the current treatment of choice; most patients make a full recovery within two years.

Cite this article: Bone Joint J 2014;96-B:950–5.

There are many causes of paraspinal muscle weakness which give rise to the dropped-head syndrome. In the upper cervical spine the central portion of the spinal cord innervates the cervical paraspinal muscles. Dropped-head syndrome resulting from injury to the central spinal cord at this level has not previously been described. We report two patients who were treated acutely for this condition. Both presented with weakness in the upper limbs and paraspinal cervical musculature after a fracture of C2. Despite improvement in the strength of the upper limbs, the paraspinal muscle weakness persisted in both patients. One ultimately underwent cervicothoracic fusion to treat her dropped-head syndrome.

While the cause of the dropped-head syndrome cannot be definitively ascribed to the injuries to the spinal cord, this pattern is consistent with the known patho-anatomical mechanisms of both injury to the central spinal cord and dropped-head syndrome.

We present data relating to the Bryan disc arthroplasty for the treatment of cervical spondylosis in 46 patients.

Patients with either radiculopathy or myelopathy had a cervical discectomy followed by implantation of a cervical disc prosthesis. Patients were reviewed at six weeks, six months and one year and assessment included three outcome measures, a visual analogue scale (VAS), the short form 36 (SF-36) and the neck disability index (NDI). The results were categorised according to a modification of Odom’s criteria. Radiological evaluation, by an independent radiologist, sought evidence of movement, stability and subsidence of the prosthesis.

A highly significant difference was found for all three outcome measurements, comparing the pre-operative with the post-operative values: VAS (Z = 6.42, p < 0.0001), SF-36 (mental component) (Z = −5.02, p < 0.0001), SF-36 (physical component) (Z = −5.00, p < 0.0001) and NDI (Z = 7.03, p < 0.0001). The Bryan cervical disc prosthesis seems reliable and safe in the treatment of patients with cervical spondylosis.