Three-dimensional measurement of lumbar spine kinematics for fast bowlers in cricket

Bowler and coach experiential knowledge of new ball swing bowling in elite cricket

Swing bowling can influence the outcome of cricket matches, but technique characteristics and coaching practices have not been investigated at an elite level. This study aimed to provide insight into the perceived technique parameters, coaching practices and variables contributing to conventional new ball swing bowling in elite cricket. Six Australian Test match fast bowlers and six Australian international and national-level coaches were interviewed. A reflexive thematic analysis of interview transcripts generated themes associated with swing bowling. Most bowlers reported their technique allows them to naturally create either inswing or outswing, with technique variations used to create swing in the opposite direction. To increase delivery effectiveness, bowlers and coaches recommended pitching the ball closer to the batter in length and varying release positions along the crease. Coaches recommended making individualised technique adjustments, but suggested all bowlers could benefit from maintaining balance and forward momentum to create a consistent release position in repeated deliveries. This study could inform training strategies to alter techniques and improve swing bowling performance. Future research should investigate the physical qualities of fast bowlers and use biomechanical analyses to provide a deeper understanding of swing bowling.

Effects of vibration-based biofeedback on multifidus muscle activity and pelvic tilt angle in subjects with hip flexion limitation

BACKGROUND

Sedentary work may lead to low back pain. In particular, a slumped sitting position may exacerbate low back pain because of tissue damage caused by excessive lumbar flexion and posterior pelvic tilting. Subjects with low back pain may have excessive changes in the lumbopelvic posture and back muscle activity in the sitting position.

OBJECTIVE

The purpose of this study was to compare the effects of vibration-based biofeedback using a motion sensor belt and no biofeedback on multifidus (MF) muscle activity and pelvic tilt angle during typing.

METHODS

Thirty subjects with low back pain accompanied by hip flexion limitation (15 each in the biofeedback and non-biofeedback groups) were enrolled. Electromyography was used to investigate MF muscle activity before and after typing for 30 min. Pelvic tilt was measured after typing in a sitting position for 30 min. Independent t-tests were used to compare MF muscle activity, and pelvic and second sacrum tilt angles, between the biofeedback and non-biofeedback groups.

RESULTS

After typing for 30 min, changes in MF muscle activity (11.45% and -7.19% for the biofeedback and nonbiofeedback groups, respectively) and pelvic and second sacrum tilt angles (3.15∘ and 4.12∘ for the biofeedback group and -11.05∘ and -18.16∘ for the non-biofeedback group, respectively) were significantly smaller in the biofeedback than non-biofeedback group (p< 0.05).

CONCLUSION

Vibration-based biofeedback minimizes the reduction in MF muscle activity and changes in pelvic and second sacrum tilt angles during typing in individuals with low back pain accompanied by hip flexion limitation.

Bone health and asymmetry in elite female cricketers

The aim of this study is to determine if bone mineral density (BMD) and bone asymmetry differs between female cricket fast bowlers, spin bowlers and batters. BMD was determined at the total body, lumbar spine, and proximal femurs in 12 fast bowlers, 13 batters and 11 spin bowlers from pre-season DXA scans. High Z-scores at the total body, lumbar spine, and proximal femur were observed in all cricketers (mean Z-scores: +1.4 to +3.3) compared with a general age matched reference population. Fast bowlers had significantly greater BMD on the contralateral side of the lumbar spine compared with the ipsilateral side (p = 0.001, 5.9 - 12.1%). No asymmetry was found between hips in all groups. All cricket positions demonstrated high BMD at all measured sites. The lumbar spine of fast bowlers is asymmetric, with significantly greater BMD on the contralateral side of the spine, particularly at L4, possibly in response to the asymmetric lumbar loading patterns observed in bowling.HIGHLIGHTS Elite female cricketers demonstrate high BMD at total body, lumbar spine and proximal femur sites, regardless of playing position compared with a general age and ethnic group matched reference populationFast bowlers have greater BMD on the contralateral (opposite bowling arm) side of the lumbar spine compared with the ipsilateral side, while a symmetrical pattern was observed in spin bowlers and batters.No asymmetry in BMD or section modulus between hips was observed at any proximal femur site for any cricket position.

Effects of abdominal drawing-in maneuver with or without prior iliopsoas stretching on gluteus maximus activity during prone hip extension

BACKGROUND

Prone hip extension (PHE) has been investigated to strengthen the hip joint and back extensor muscles. However, it has not been compared with various PHE exercises in individuals with iliopsoas shortness.

OBJECTIVE

This study compared pelvic compensation and hip and back extensor muscle activities in individuals with iliopsoas shortness during prone hip extension (PHE) using the abdominal drawing-in maneuver alone (PHEA) and after iliopsoas stretching (PHEAS).

METHODS

Twenty-five individuals with iliopsoas shortness were included in the study. Electromyography was used to investigate bilateral erector spinae (ES) and ipsilateral gluteus maximus (GM), biceps femoris (BF), and semitendinosus (ST) muscles during PHE, PHEA, and PHEAS. Pelvic anterior tilting and rotation angles were measured during each PHE exercise via electromagnetic motion tracking. A modified Thomas test was used to examine the hip extension angle before and after iliopsoas stretching. One-way repeated-measures analysis of variance was used to investigate differences in pelvic anterior tilting and rotation angle and in hip and back extensor muscle activities among PHE, PHEA, and PHEAS. The level of statistical significance was set at α= 0.01.

RESULTS

GM muscle activity was significantly greater with PHEAS, compared to PHE and PHEA (p< 0.01). Bilateral ES and ipsilateral BF and ST muscle activities were significantly reduced with PHEAS, compared to PHE and PHEA (p< 0.01). Anterior pelvic tilting and rotation angles were significantly reduced with PHEAS, compared to PHE and PHEA (p< 0.01).

CONCLUSIONS

PHEAS is recommended to selectively strengthen GM muscles with minimal BF and ST muscle activities and pelvic compensation in individuals with iliopsoas shortness. The abdominal drawing-in maneuver (ADIM) after iliopsoas stretching is more efficient than ADIM alone during PHE, especially in individuals with iliopsoas shortness.

Measurement of uni-planar and sport specific trunk motion using magneto-inertial measurement units: The concurrent validity of Noraxon and Xsens systems relative to a retro-reflective system

BACKGROUND

There is a range of magneto-inertial measurement unit (MIMU) systems commercially available, however sensor specifications and fusion methods vary considerably between manufacturers. Such variability can influence the concurrent validity of MIMUs relative to reference standard measurement devices. Different MIMUs have been compared during static or low-velocity conditions, with higher-velocity movements assessed in robotic-based studies. However, there is a need for the concurrent validity of higher-velocity movements to be established in human-based studies.

RESEARCH QUESTION

This study aimed to assess the concurrent validity of two commercial MIMU systems (Noraxon and Xsens), relative to a 'gold-standard' retro-reflective motion capture system, when measuring trunk angles during uni-planar range of motion (ROM) and cricket bowling, which involves high-speed, multi-planar movements.

METHODS

For this criterion-based validity study, both MIMU systems incorporated comparable sensor specifications and employed Kalman filter sensor fusion algorithms. The MIMU based angles were compared with angles derived from concurrently captured three-dimensional retro-reflective data for 10 fast-medium bowlers. Statistical parametric mapping and root mean squared differences (RMSD) were computed for both MIMU systems.

RESULTS

One-dimensional statistical parametric mapping showed no significant differences for angles from both MIMU systems when compared with retro-reflective based angle outputs. The MIMU systems produced ROM RMSDs between 1.4 ± 1.0° and 2.6 ± 1.5°. One system displayed RMSDs between 4.6 ± 1.4° and 7.4 ± 1.9° during bowling, indicating functionally relevant differences to retro-reflective derived angles. There were some small but statistically significant differences in RMSDs between the MIMU systems.

SIGNIFICANCE

MIMU-based angle accuracy is poorer during high-speed, multi-planar movement than uni-planar tasks. Comparable MIMU systems can produce varying measurements during ROM and bowling tasks. It is likely that varying sample rates and sensor fusion algorithm parameters contributed to the differences.

Functional calibration does not improve the concurrent validity of magneto-inertial wearable sensor-based thorax and lumbar angle measurements when compared with retro-reflective motion capture

 Magneto-inertial measurement unit (MIMU) systems allow calculation of simple sensor-to-sensor Euler angles, though this process does not address sensor-to-segment alignment, which is important for deriving meaningful MIMU-based kinematics. Functional sensor-to-segment calibrations have improved concurrent validity for elbow and knee angle measurements but have not yet been comprehensively investigated for trunk or sport-specific movements. This study aimed to determine the influence of MIMU functional calibration on thorax and lumbar joint angles during uni-planar and multi-planar, sport-specific tasks. It was hypothesised that functionally calibrating segment axes prior to angle decomposition would produce smaller differences than a non-functional method when both approaches were compared with concurrently collected 3D retro-reflective derived angles. Movements of 10 fast-medium cricket bowlers were simultaneously recorded by MIMUs and retro-reflective motion capture. Joint angles derived from four different segment definitions were compared, with three incorporating functionally defined axes. Statistical parametric mapping and root mean squared differences (RMSD) quantified measurement differences one-dimensionally and zero-dimensionally, respectively. Statistical parametric mapping found no significant differences between MIMU and retro-reflective data for any method across bowling and uni-planar trunk movements. The RMSDs for the functionally calibrated methods and non-functional method were not significantly different. Functional segment calibration may be unnecessary for MIMU-based measurement of thorax and lumbar joint angles.

Validity and reliability of innovative field measurements of tibial accelerations and spinal kinematics during cricket fast bowling

The use of inertial sensors in fast bowling analysis may offer a cheaper and portable alternative to current methodologies. However, no previous studies have assessed the validity and reliability of such methods. Therefore, this study aimed to assess the validity and reliability of collecting tibial accelerations and spinal kinematics using inertial sensors during in vivo fast bowling. Thirty-five elite male fast bowlers volunteered for this study. An accelerometer attached to the skin over the tibia was used to determine impacts and inertial sensors over the S1, L1 and T1 spinous processes used to derive the relative kinematics. These measurements were compared to optoelectronic and force plate data for validity analysis. Most acceleration and kinematics variables measured report significant correlations > 0.8 with the corresponding gold standard measurement, with intraclass correlation coefficients greater than 0.7. Low standard error of measurement and consequently small minimum detectable change (MDC) values were also observed. This study demonstrates that inertial sensors are as valid and reliable as current methods of fast bowling analysis and may provide some advantages over traditional methods. The novel metrics and methods described in this study may aid coaches and practitioners in the design and monitoring of fast bowling technique.

Graphical abstract illustrating the synopsis of the findings from this paper.

Validity and reliability of a sensor-based electronic spinal mobility index for axial spondyloarthritis

OBJECTIVE

To evaluate the validity and reliability of inertial measurement unit (IMU) sensors in the assessment of spinal mobility in axial spondyloarthritis (axSpA).

METHODS

A repeated measures study design involving 40 participants with axSpA was used. Pairs of IMU sensors were used to measure the maximum range of movement at the cervical (Cx) and lumbar (Lu) spine. A composite IMU score was defined by combining the IMU measures. Conventional metrology and physical function assessment were performed. Validation was assessed considering the agreement of IMU measures with conventional metrology and correlation with physical function. Reliability was assessed using intra-class correlation coefficients (ICCs).

RESULTS

The composite IMU score correlated closely (r = 0.88) with the BASMI. Conventional Cx rotation and lateral flexion tests correlated closely with IMU equivalents (r = 0.85, 0.84). All IMU movement tests correlated strongly with BASFI, while this was true for only some of the BASMI tests. The reliability of both conventional and IMU tests (except for chest expansion) ranged from good to excellent. Test-retest ICCs for individual conventional tests varied between 0.57 and 0.91, in comparison to a range from 0.74 to 0.98 for each of the IMU tests. Each of the composite regional IMU scores had excellent test-retest reliability (ICCs=0.94-0.97), comparable to the reliability of the BASMI (ICC=0.96).

CONCLUSION

Cx and Lu spinal mobility measured using wearable IMU sensors is a valid and reliable assessment in multiple planes (including rotation), in patients with a wide range of axSpA severity.

Lumbar spine abnormalities and facet joint angles in asymptomatic elite junior tennis players

BACKGROUND

Lumbar spine abnormalities, in particular stress fractures to the pars interarticularis, are common in elite junior tennis players, though the difference in prevalence between males and females remains unclear. Further, facet joint orientation appears to be a possible option for recognizing which players might go on to present with a pars stress fracture. Given the link between pars stress fractures and low back pain in tennis players, it appears logical to explore the link between facet joint angle and pars abnormalities. Thus, the purpose of this study was to describe the prevalence of lumbar spine abnormalities and explore the relationship between facet joint orientation and pars abnormalities in elite adolescent tennis players.

METHODOLOGY

Lumbar spine MRI images of 25 elite junior tennis players were obtained and distributed between five radiologists for analysis. Descriptive comparisons and confidence intervals were used to describe the prevalence of the abnormalities. A generalized linear regression model was conducted to investigate the relationship between lumbar pars abnormalities and lumbar facet joint angles.

RESULTS

Sixteen (64%) of 25 players were found to have at least one lumbar spine abnormality. Pars abnormalities affected 36% of players while bone marrow edema was found in 24% of players. Disc herniation, disc degeneration, and facet joint degeneration were diagnosed in 20%, 44%, and 24% of players respectively. Lastly, one player (4%) was diagnosed with spondylolisthesis. Females had significantly larger facet joint angles across L3/4 L5/S1 compared to males (p < 0.01). Further, those who had pars abnormalities had larger facet joint angles compared to those who did not (p < 0.001).

CONCLUSION

Disc degeneration, pars abnormalities, including bone marrow edema, and facet joint degeneration were common findings among elite adolescent tennis players. Additionally, this study is the first to discover that pars abnormalities are linked to facet joint angle in elite adolescent tennis players. This finding might assist in identifying tennis players at a greater risk of developing lumbar spine pars abnormalities in the future.

Ground reaction force, spinal kinematics and their relationship to lower back pain and injury in cricket fast bowling: A review

BACKGROUND

Fast bowlers display a high risk of lower back injury and pain. Studies report factors that may increase this risk, however exact mechanisms remain unclear.

OBJECTIVE

To provide a contemporary analysis of literature, up to April 2016, regarding fast bowling, spinal kinematics, ground reaction force (GRF), lower back pain (LBP) and pathology.

METHOD

Key terms including biomechanics, bowling, spine and injury were searched within MEDLINE, Google Scholar, SPORTDiscuss, Science Citation Index, OAIster, CINAHL, Academic Search Complete, Science Direct and Scopus. Following application of inclusion criteria, 56 studies (reduced from 140) were appraised for quality and pooled for further analysis.

RESULTS

Twelve times greater risk of lumbar injury was reported in bowlers displaying excessive shoulder counter-rotation (SCR), however SCR is a surrogate measure which may not describe actual spinal movement. Little is known about LBP specifically. Weighted averages of 5.8 ± 1.3 times body weight (BW) vertically and 3.2 ± 1.1 BW horizontally were calculated for peak GRF during fast bowling. No quantitative synthesis of kinematic data was possible due to heterogeneity of reported results.

CONCLUSIONS

Fast bowling is highly injurious especially with excessive SCR. Studies adopted similar methodologies, constrained to laboratory settings. Future studies should focus on methods to determine biomechanics during live play.

A detailed description of the short-term musculoskeletal and cognitive effects of prolonged standing for office computer work

Due to concerns about excessive sedentary exposure for office workers, alternate work positions such as standing are being trialled. However, prolonged standing may have health and productivity impacts, which this study assessed. Twenty adult participants undertook two hours of laboratory-based standing computer work to investigate changes in discomfort and cognitive function, along with muscle fatigue, movement, lower limb swelling and mental state. Over time, discomfort increased in all body areas (total body IRR [95% confidence interval]: 1.47[1.36-1.59]). Sustained attention reaction time (β = 18.25[8.00-28.51]) deteriorated, while creative problem solving improved (β = 0.89[0.29-1.49]). There was no change in erector spinae, rectus femoris, biceps femoris or tibialis anterior muscle fatigue; low back angle changed towards less  lordosis, pelvis movement increased, lower limb swelling increased and mental state decreased. Body discomfort was positively correlated with mental state. The observed changes suggest replacing office work sitting with standing should be done with caution. Practitioner Summary: Standing is being used to replace sitting by office workers; however, there are health risks associated with prolonged standing. In a laboratory study involving 2 h prolonged standing discomfort increased (all body areas), reaction time and mental state deteriorated while creative problem-solving improved. Prolonged standing should be undertaken with caution.

Are shoulder counter rotation and hip shoulder separation angle representative metrics of three-dimensional spinal kinematics in cricket fast bowling?

This study aimed to investigate the relationship between shoulder counter-rotation (SCR), hip shoulder separation (HSS) and three-dimensional spinal kinematics during fast bowling in cricket. Thirty five elite male fast bowlers were analysed using three-dimensional inertial sensors on the spine. Lumbar, thoracic and thoracolumbar kinematics were determined during the delivery stride. Spearman's pairwise correlations displayed significant associations between SCR, thoracic and thoracolumbar lateral flexion between the back foot impact and max contralateral rotation phase of the delivery stride (r_s = -.462 and -.460). HSS and thoracolumbar lateral flexion displayed a significant correlation between back foot impact and max contralateral rotation (r_s = -.552). No other significant correlations were observed. These results suggest SCR and HSS are modestly related to lateral flexion, leaving a large component of SCR and HSS unrelated to specific three-dimensional spinal kinematics. It is possible that this represents changes in whole spinal orientation and not resultant spinal motion. Despite this, SCR remains the only metric currently related to injury and therefore is important; however it is only a very modest proxy for more traditional descriptions of spinal motion.

Lumbopelvic muscle activation patterns in adolescent fast bowlers

INTRODUCTION

Adolescent fast bowlers are prone to sustaining lumbar injuries. Numerous components have been identified as contributing factors; however, there is limited empirical evidence outlining how the muscles of the lumbopelvic region, which play a vital role in stabilising the spine, function during the bowling action and the influence of such activation on injuries in the fast bowler.

METHODS

Surface electromyography was utilised to measure the function of the lumbar erector spinae, lumbar multifidus, gluteus medius and gluteus maximus muscles bilaterally during the fast bowling action in a group of 35 cricket fast bowlers aged 12-16 years.

RESULTS

Two prominent periods of activation occurred in each of the muscles examined. The period of greatest mean activation in the erector spinae and multifidus occurred near back foot contact (BFC) and within the post-ball-release (BR) phase. The period of greatest mean activation for the gluteus medius and gluteus maximus occurred during phases of ipsilateral foot contact.

DISCUSSION

The greatest periods of muscle activation in the paraspinal and gluteal muscles occurred at times where vertical forces were high such as BFC, and in the phases near BR where substantial shear forces are present.

CONCLUSION

The posterior muscles within the lumbopelvic region appear to play a prominent role during the bowling action, specifically when compressive and shear forces are high. Further research is required to substantiate these findings and establish the role of the lumbopelvic muscles in the aetiology of lumbar injury in the cricket fast bowler.

Are Fast-Bowlers Prone to Back Injuries? Prevalence of Lumbar Spine Injuries in Fast-Bowlers: Review of MRI-Based Studies

Background:

Fast-bowlers in cricket subject their spines to repetitive stress.

Objectives:

The aim of this study was to review the prevalence of lumbar spine injuries among fast-bowlers.

Materials and Methods:

Medline and embase searches were performed. Further, the authors canvassed the reference list of available articles and used other search engines such as Google Scholar to identify a total of nine studies.

Results:

The prevalence of lumbar disc degeneration in fast-bowlers ranges from 21-65% with an incidence rate of 15% per year, and the prevalence of lumbar spine bony abnormalities ranges from 24-81%. Factors associated with lumbar spine injury in fast-bowlers are classified into un-modifiable (age) and modifiable (more intense bowling workload and mixed-bowling technique).

Conclusions:

Fast-bowlers have a high prevalence of lumbar spine injuries. Appropriate interventions, such as educational sessions, may be able to modify risk factors such as bowling workload and bowling technique and thus reduce injury prevalence.

An experimental study investigating the effect of pain relief from oral analgesia on lumbar range of motion, velocity, acceleration and movement irregularity

Background

Movement alterations are often reported in individuals with back pain. However the mechanisms behind these movement alterations are not well understood. A commonly cited mechanism is pain. The aim of this study was to investigate the effect of pain reduction, from oral analgesia, on lumbar kinematics in individuals with acute and chronic low back pain.

Methods

A prospective, cross-sectional, experimental repeated-measures design was used. Twenty acute and 20 chronic individuals with low back pain were recruited from General Practitioner and self-referrals to therapy departments for low back pain. Participants complained of movement evoked low back pain. Inertial sensors were attached to the sacrum and lumbar spine and used to measure kinematics. Kinematic variables measured were range of motion, angular velocity and angular acceleration as well as a determining movement irregularity (a measure of deviation from smooth motion). Kinematics were investigated before and after administration of oral analgesia to instigate pain reduction.

Results

Pain was significantly reduced following oral analgesia. There were no significant effects on the kinematic variables before and after pain reduction from oral analgesia. There was no interaction between the variables group (acute and chronic) and time (pre and post pain reduction).

Conclusion

The results demonstrate that pain reduction did not alter lumbar range of motion, angular velocity, angular acceleration or movement irregularity questioning the role of pain in lumbar kinematics.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-304) contains supplementary material, which is available to authorized users.

High Prevalence of Disc Degeneration and Spondylolysis in the Lumbar Spine of Professional Beach Volleyball Players

Background:

Beach volleyball is an intensive sport with high impact on the lumbar spine. Low back pain (LBP) is frequent among elite players. Increased prevalence of pathological changes on magnetic resonance imaging (MRI) in the lumbar spine of elite athletes has been reported. Hypothesis: There is an increased prevalence of disc degeneration and spondylolysis in the MRI of the lumbar spine of professional beach volleyball players.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

Twenty-nine fully competitive professional male volleyball players (mean age, 28 years) completed outcomes questionnaires and underwent a complete clinical examination and an MRI of their lumbar spine.

Results:

Whereas 86% of players suffered from LBP during their career, the incidence of LBP in the last 4 weeks was 35%. Pain rated using a visual analog scale (VAS) averaged 3 points (range, 0-8). Twenty-three of 29 players (79%) had at least 1 degenerated disc of Pfirrmann grade ≥3. The most affected spinal levels were L4-5 in 14 (48%) and L5-S1 in 15 players (52%); both levels were involved in 5 players (17%). Six of 29 (21%) players showed a spondylolysis grade 4 according to the Hollenburg classification; there was evidence of spondylolisthesis in 2 players. There was no significant correlation between LBP and MRI abnormalities.

Conclusion:

In the lumbar spine MRI of professional beach volleyball players, the prevalence of disc degeneration is 79%. Spondylolysis (21%) is up to 3 times higher compared with the normal population. Abnormal MRI findings did not correlate with LBP, thus MRIs have to be interpreted with caution.

The use of inertial sensors system for human motion analysis

Objective:

The aim of this article is to review systematically and appraise critically the literature surrounding the research, comparing inertial sensors with any kind of gold standard; this gold standard has to be a tool for measuring human movement (e.g. electrogoniometry, optoelectronic systems, electromagnetic systems, etc.).

Method:

A MEDLINE, EMBASE, CINAHL, PEDRo and SCOPUS search of published English language articles was conducted, which focused on articles that compared inertial sensors to any kind of gold standard (e.g. electrogoniometry, optoelectronic systems, electromagnetic systems, etc.), from 2000 to 2010. Two independent reviewers completed the study selection, quality appraisal and data extraction. The Critical Appraisal Skills Programme Español tool was used to assess study quality, and a reliability comparison between the systems was made.

Results:

Fourteen out of 242 articles were reviewed, which displayed a similar threat to validity, relating to sample selection and operator blinding. Other study limitations are discussed. A comparison between the different systems showed good agreement across a range of tasks and anatomical regions.

Conclusions:

This review concludes that inertial sensors can offer an accurate and reliable method to study human motion, but the degree of accuracy and reliability is site and task specific.

Cognitive functional therapy for the management of low back pain in an adolescent male rower: a case report

STUDY DESIGN

Case report.

BACKGROUND

Contemporary low back pain models propose that the experience of and responses to pain result from a complex interaction of biopsychosocial factors. This supports the need for a management approach that addresses the biological, psychological, and social components that may be related to the pain disorder. This case report demonstrates the application of, and outcomes associated with, a cognitive functional intervention that considers neurophysiological, physical, psychosocial, cognitive, and lifestyle dimensions for the management of a rower with nonspecific chronic low back pain.

CASE DESCRIPTION

An adolescent male club-level rower with nonspecific chronic low back pain was classified as having a motor control impairment with a lower lumbar compressive-loading pattern in flexion. Evaluation of this patient included ergometer rowing analysis (clinical and laboratory) before and after an 8-week intervention, and outcome measures at a 12-week follow-up. The intervention consisted of a cognitive functional approach that targeted optimization of movement behavior, providing the rower with alternative movement strategies to minimize sustained flexion loading.

OUTCOMES

Reduced temporal summation of pain while ergometer rowing and reduced functional disability were observed preintervention to 12 weeks postintervention by changes in Roland-Morris Disability Questionnaire score (12/24 to 1/24) and the Patient-Specific Functional Scale (4/30 to 26/30), and associated improvements in lower-limb and back muscle endurance and changes in hip and spinopelvic kinematics during ergometer rowing. In particular, there was a greater use of available range of movement in the lumbar spine postintervention.

DISCUSSION

The cognitive functional intervention for this patient resulted in reduced pain and functional disability related to ergometer rowing, which was associated with a change in lumbar kinematics and improved lower-limb and back muscle endurance. The results suggest that providing the rower with greater use of his available range of movement may enhance load distribution during the drive phase of rowing. Registered at Australian New Zealand Clinical Trials Registry (ACTRN12609000565246).

LEVEL OF EVIDENCE

Therapy, level 4.

Validity and reliability of the Spineangel lumbo-pelvic postural monitor

OBJECTIVE

to determine the reliability and the concurrent validity of the Spineangel lumbo-pelvic postural monitoring device.

METHODS

the dynamic lumbo-pelvic posture of 25 participants was simultaneously monitored by the Spineangel and Fastrak devices. Participants performed six different functional tasks in random order. Within-task, within-session and between-day intraclass correlation coefficients (ICC(3,1), ICC(3,5), ICC(2,5), respectively) reliability were calculated for Spineangel measurements. Concurrent validity of the Spineangel was assessed by means of a Bland and Altman plot and by means of Pearson's correlation coefficient and paired t-test.

RESULTS

within-task, within-session and between-day ICC for the Spineangel were found to be excellent (>0.93). The Spineangel and Fastrak pelvic measurements were found to have a good correlation (R = 0.77).

CONCLUSION

the Spineangel is a reliable and valid device for monitoring general lumbo-pelvic movements when clipped on the belt or waistband of workers' clothing during various occupational activities.

PRACTITIONER SUMMARY

The Spineangel can be used for assessing lumbo-pelvic posture during work or daily-life activities. This device was found to provide reliable and valid measurements for lumbo-pelvic movements. Further research is required to determine whether the use of this device is clinically relevant for patients presenting with low back pain.

The use of pMRI to validate the identification of palpated bony landmarks

Accurate palpation of lumbar spinous processes (SPs) is a key component of spinal assessment. It is also vital for the accurate measurement of spinal motion when using external skin marker-based measurement systems, which are being increasingly used to understand low back disorders and their management. The aim was to assess the accuracy of lumbar spinous process (SP) palpation using positional magnetic resonance imagery (MRI) (pMRI). Two experienced manual therapists palpated the L4 SP of nine pain-free participants in standing and prone lying. For each position, an MRI marker was attached over the SP and pMRI scanning was conducted. The position of the marker in relation to L4 on the MRI images was visually inspected, and measurements (mm) of the vertical distance from the superior/inferior aspect of the marker to the superior/inferior aspect of the L4 SP were used to determine palpation accuracy. 71% of Markers were correctly placed over the L4 SP. The magnitude of error for incorrectly placed markers was small, with the largest median distance of 2.7 mm (interquartile range (IQR) 0-3.6) recorded for one of the therapists palpating in prone lying. 100% of markers were correctly placed either on L4 or within one SP in height. pMRI is useful for investigating the accuracy of SP palpation in positions relevant to clinical and research practice.

A novel approach to the clinical evaluation of differential kinematics of the lumbar spine

Clinical measurement of lumbar motion has traditionally been limited to range of motion (ROM). Despite this, deficits in angular velocities and accelerations are more pronounced compared to ROM in low back pain (LBP) sufferers. There is increasing interest in movement quality among manual therapists and therefore the ability to measure angular velocities and accelerations within the clinical environment is becoming increasingly important. The aims of this study were to (1) investigate the reliability of a clinic based inertial sensor system to measure ROM along with angular velocities and accelerations in low back pain sufferers; (2) introduce the feasibility and reliability of using the relationship between ROM and velocity to investigate movement trajectory and irregularity. Forty LBP sufferers completed three trials of spinal movements and lifting. The ROM curve was differentiated and double differentiated to yield angular velocities and accelerations. Repeated measures reliabilities were determined by comparisons of kinematic curves as well as peak values. ROM and angular velocity relationships were investigated for their use in describing the movement trajectory and irregularity. Results show excellent similarities of ROM and angular velocity curves and moderate-to-good similarities for angular acceleration curves. Peak value similarities were excellent with small error measurements for all variables. The quantification of ROM-angular velocity plots was reliable with small mean absolute differences in motion irregularity scores. Such a method was able to demonstrate differences in movement irregularity. This method provides clinicians with the ability to yield important additional movement related information including angular velocity, acceleration and movement irregularity.

Dynamic lumbar curvature measurement in acute and chronic low back pain sufferers

OBJECTIVES

(1) To determine the reliability of a novel fiber-optic method to dynamically measure lumbar curvature in low back pain (LBP) sufferers, and (2) to investigate the dynamic lumbar curvature in acute and chronic LBP sufferers.

DESIGN

Cross-sectional study.

SETTING

Physiotherapy clinic.

PARTICIPANTS

Acute (n=20) and chronic (n=20) LBP sufferers recruited from general practitioner and therapist referrals.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

A fiber-optic device was used to measure curvature through time during flexion, lifting, and extension movements. Repeated-measures reliability for curvature-time curves was tested using coefficients of multiple correlation (CMCs) and root mean square error, and for peak curvature values intraclass correlation coefficients (ICCs) and mean absolute errors were used. Acute and chronic LBP groups were compared using peak curvatures and sequencing of curvature change.

RESULTS

The fiber-optic method was shown to be highly reliable in measuring both whole lumbar and lower lumbar curvature with CMC values >.81 and ICC values >.99. Chronic LBP sufferers displayed greater peak curvatures during flexion and lifting for the whole lumbar spine and lifting for the lower lumbar spine. The sequencing behavior demonstrated that the quartile of movement associated with the greatest curvature change was the second for flexion and lifting and first and second for extension across both groups. No significant differences in sequencing were demonstrated between the 2 groups.

CONCLUSIONS

This method is reliable for dynamic lumbar curvature measurement in back pain sufferers and is a viable option for clinicians. Acute LBP sufferers display less kyphosis during flexion and lifting. Sequencing of curvature change is similar across the 2 groups.

Measurement of lumbar spine range of movement and coupled motion using inertial sensors - a protocol validity study

Measurement of spinal lumbar range of movement is useful in clinical examination of the spine and for monitoring changes in spinal movement characteristics of individuals over time, particularly in the research context. As the spine exhibits six degrees of movement, three dimensional measurements provide additional information that could benefit the study of spinal conditions. Inertial measurement systems present an innovative method of spinal motion measurement. These systems are small and portable, and of low cost compared to laboratory based three dimensional measurement systems such as electromagnetic and opto-electronic systems. The present study aimed to validate the use of inertial measurement systems in three dimensional spinal range of movement measurement using an electromagnetic tracking system as a reference. Twenty-six healthy participants had their lumbar spine range of movement measured using both an inertial measurement system and an electromagnetic tracking system. Measurements taken by the inertial measurement system were found to be highly correlated with the electromagnetic tracking system (overall regression R(2) 0.999, p < 0.005). Measurements showed strong agreement (mean differences between -0.81° and 1.26°) and produced no significant difference from the electromagnetic tracking system (paired t-test p > 0.05). The ranges of movement measured were also highly comparable to those reported in the literature. Inertial measurement systems that consist of triaxial gyroscopes, accelerometers and magnetometers are concluded to be valid tools for three dimensional spinal range of movement measurement within or outside of the laboratory settings due to their cost, size and portability.

The imaging and management of nonconsecutive pars interarticularis defects: a case report and review of literature

BACKGROUND CONTEXT

Lumbar spondylolysis is a well-recognized condition occurring in adolescents because of repetitive overuse in sports. Multiple-level spondylolysis involving consecutive lower lumbar segments are rare. Several authors have reported failure of conservative treatment in the management of multiple-level pars fractures.

STUDY DESIGN

A case report and review of previous literature is presented.

OBJECTIVE

The objectives of this case report were to present a rare case of pars fracture involving nonconsecutive segments and discuss image findings and treatment.

METHODS

The patent's history, clinical examination, computed tomography (CT), magnetic resonance imaging (MRI) findings, and treatment are reported. We also discuss the pathogenesis, various treatment options, and review the literature.

RESULTS

We present the fourth case of bilateral pars fractures involving nonconsecutive lower lumbar spine segments of L3 and L5, in a 16-year-old young adolescent footballer who presented with 4-month history of constant low back pain. After 1 year of conservative management, the more acute fractures at L3 showed complete bony union, symptomatic pain relief, and return to full sporting activity.

CONCLUSION

We report a rare case of bilateral pars fractures involving nonconsecutive segments. Multiplane reconstruction of CT images and MRI are very useful in planning treatment and follow-up. Conservative management may be used to treat multilevel nonconsecutive pars fractures.

Differences in spinopelvic kinematics in sweep and scull ergometer rowing

OBJECTIVE

The spinopelvic kinematics of sweep and scull have yet to be investigated, despite evidence suggesting that sweep rowing may be provocative for low back pain (LBP). The aim of this study was to determine whether differences existed in spinopelvic kinematics in high-level rowers without LBP in sweep and scull ergometer rowing.

DESIGN

Repeated measures study.

SETTING

Institute of Sport Laboratory.

PARTICIPANTS

Ten high-level rowers.

INTERVENTIONS

Kinematics of the pelvis, lower lumbar, upper lumbar, and lower thoracic regions during the drive phase of the rowing stroke were measured while rowing on an interchangeable sweep/scull ergometer.

MAIN OUTCOME MEASURES

Total and segmental spinopelvic kinematics.

RESULTS

Sweep rowing showed greater lateral bend (P < 0.05) throughout the stroke, which was predominately due to movement of the upper lumbar and lower thoracic regions. Furthermore, sweep rowing displayed a greater magnitude (P < 0.05) of axial rotation at the catch (created at the pelvis). Both sweep and scull rowing showed values close to end range flexion for the lower lumbar spine at the catch and early drive phases. No difference (P > 0.05) was evident in lateral bend or axial rotation values for the lower lumbar region.

CONCLUSIONS

Some differences exist in spinopelvic kinematics between sweep and scull ergometer rowing. However, it may be speculated that the lack of differences in lateral bend and axial rotation at the lower lumbar spine in sweep rowing may represent an adaptive and protective approach of experienced rowers. This may be the focus of future research studies.

In vivo laboratory validation of the physiometer: a measurement system for long-term recording of posture and movements in the workplace

Posture and movement are thought to be important risk factors for the development of work-related musculoskeletal disorders. Whole day occupational exposure assessment has typically used self-report or observation techniques, but the need for more accurate measurement is now recognised. The aim of this study was to compare the kinematic recordings of a frequently used field system (physiometer) with two laboratory-based systems (Fastrak and Peak) in vivo. Head, thorax and right arm kinematics were recorded simultaneously by the three systems whilst a subject performed 27 single and multiple plane physiological and simulated daily living task movement trials. Errors observed in the Fastrak and Peak data included gimbal lock and quadrant errors. Physiometer data errors included undervalues, overvalues and temporal errors of slow response and resonance. All three systems showed some cross-talk. Agreement between the physiometer and the other systems was generally high for physiological movements (R(2) > 0.8) and less for functional movements (R(2) > 0.5). STATEMENT OF RELEVANCE: The physiometer recording device can provide an indication of posture across time in the workplace; however, its accuracy is limited, particularly during functional movements. Further technology should be developed to unobtrusively capture accurate all day 3-D kinematics.

Nucleus pulposus deformation in response to lumbar spine lateral flexion: an in vivo MRI investigation

Whilst there are numerous studies examining aspects of sagittal plane motion in the lumbar spine, few consider coronal plane range of motion and there are no in vivo reports of nucleus pulposus (NP) displacement in lateral flexion. This study quantified in vivo NP deformation in response to side flexion in healthy volunteers. Concomitant lateral flexion and axial rotation range were also examined to evaluate the direction and extent of NP deformation. Axial T2- and coronal T1-weighted magnetic resonance images (MRI) were obtained from 21 subjects (mean age, 24.8 years) from L1 to S1 in the neutral and left laterally flexed position. Images were evaluated for intersegmental ranges of lateral flexion and axial rotation. A novel methodology derived linear pixel samples across the width of the disc from T2 images, from which the magnitude and direction of displacement of the NP was determined. This profiling technique represented the relative hydration pattern within the disc. The NP was displaced away from the direction of lateral flexion in 95/105 discs (p < 0.001). The extent of NP displacement was associated strongly with lateral flexion at L2-3 (p < 0.01). The greatest range of lateral flexion occurred at L2-3, L3-4 and L4-5. Small intersegmental ranges of axial rotation occurred at all levels, but were not associated with NP displacement. The direction of NP deformation was highly predictable in laterally flexed healthy lumbar spines; however, the magnitude of displacement was not consistent with the degree of intersegmental lateral flexion or rotation.

Feasibility of using inertial sensors to assess human movement

The aim of this study was to determine the suitability of inertial sensors for motion analysis research. Inertial sensors (Xsens Technologies, Netherlands) consisting of 3D gyroscopes, accelerometers and a magnetometer were compared against an electromagnetic motion tracking system (Fastrak, Polhemus, USA) for measuring motions of an artificial hinge joint and random 3D motions. Subsequently, to assess the feasibility of using inertial sensors for human motion analysis, the movements of the hip joint during walking were recorded in 20 normal asymptomatic subjects. The comparative study demonstrated good agreement between the inertial and electromagnetic systems. Measurements obtained for hip joint movement during walking (flexion, extension and step length) were similar to those reported in previous studies (flexion 38.8 degrees , extension 6.6 degrees , step frequency 1.02Hz). We conclude that the inertial sensors studied have the potential to be used for motion analysis and clinical research.

The lumbar paraspinal muscle morphometry of fast bowlers in cricket

OBJECTIVE

To describe the functional cross-sectional area (FCSA) of the lumbar paraspinal muscles of professional fast bowlers in cricket and to investigate the nature of any muscle asymmetry.

DESIGN

Descriptive cross-sectional between-groups study.

SETTING

The England and Wales Cricket Board.

PARTICIPANTS

Forty-six asymptomatic professional fast bowlers and 17 athletic controls.

MAIN OUTCOME MEASUREMENTS

The magnetic resonance imaging of functional cross-sectional area (FCSA) of the lumbar paraspinal muscles, and the prevalence of asymmetry (greater than 10% difference in the FCSA between the dominant and nondominant side muscles).

RESULTS

A relatively high percentage of fast bowlers had asymmetrically larger dominant side quadratus lumborum FCSAs at L1 (47%), L3 (41%), and L4 (47%). The nondominant side psoas FCSA was larger in fast bowlers at L5, and the dominant side multifidus FCSA was larger in both the fast bowlers at L3 to S1 and in the control subjects at L4 and L5.

CONCLUSIONS

There was a higher prevalence of lumbar muscle asymmetry in the fast bowler group. Paraspinal muscle asymmetry was most prevalent in the quadratus lumborum of fast bowlers, and it was also evident in the lumbar multifidus in both groups of subjects. In both muscle groups, this was consistent with hypertrophy of the dominant side muscle. This study may be used to inform prospective studies of risk factors for low back injury in athletic males and enhance the development of more accurate models of stress production in the lumbar spine during fast bowling and other asymmetrical sports.

The role of quadratus lumborum asymmetry in the occurrence of lesions in the lumbar vertebrae of cricket fast bowlers

In cricket fast bowlers an increased incidence of stress fractures or lesions in the L4 pars interarticularis is observed, which shows a strong statistical correlation with the presence of hypertrophy in the contralateral Quadratus Lumborum (QL) muscle. This study aims to find a physical explanation for this correlation. A mathematical model was used to estimate the forces and moments on the L3 and L4 vertebrae in six postures attained during fast bowling. These forces and moments were used in finite element models to estimate the stresses in the pars interarticularis. Two scenarios were examined per posture: symmetric QL muscles, and right QL muscle volume 30% enlarged. Influence of muscle activation was also investigated. QL asymmetry only correlates with significant stress increases when stress levels are relatively low. When stress levels are high, due to extreme posture or muscle activation, asymmetry only causes small stress changes, suggesting that asymmetry is not the cause of stress fractures in the pars. There are even indications that asymmetry might help to reduce stresses, but more detailed knowledge of the size and activation of the lumbar muscles is needed to confirm this.

Quadratus Lumborum Asymmetry and L4 Pars Injury in Fast Bowlers

PURPOSE

This prospective study examined the association between quadratus lumborum (QL) asymmetry and the development of symptomatic pars interarticularis lesions in the lumbar spine of adolescent cricket fast bowlers.

METHODS

Annual magnetic resonance imaging was used to measure QL volume asymmetry and for identifying pars lesions of the lumbar vertebrae in fast bowlers (N=51) and a control group of swimmers (N=18). Manual segmentation of axial images spanning the lumbar spine was performed to calculate percent QL asymmetry relative to the bowling- or throwing- (swimmers) arm side. Asymmetry above 100% indicated a larger QL volume on the bowling- (throwing) arm side.

RESULTS

The mean QL asymmetry in bowlers of 110.5% (SD=12.1%) was significantly different from the 96.6% (SD=5.0%) asymmetry in swimmers (t=6.75, P<or=0.001). In bowlers with symptomatic unilateral L4 pars lesions (N=11), which all developed opposite the bowling-arm side, the mean 124.3% (SD=8.3%) QL asymmetry exceeded the 106.7% (SD=10.1%) asymmetry in bowlers without these one-sided lesions. A logistic regression model (intercept=-22.1, P<or=0.001; asymmetry coefficient=0.18, P<or=0.001) demonstrated a significant association between increasing QL asymmetry and L4 lesions in bowlers. Receiver operating characteristic curve analysis demonstrated that QL asymmetry was an excellent predictor of L4 lesions in fast bowlers (area under curve=0.89, 95% confidence interval: 0.79, 0.98).

CONCLUSION

The strong association between QL asymmetry and the development of symptomatic unilateral L4 pars lesions in adolescent bowlers conceivably reflects a mechanical coupling between the loading milieu generating these injuries and preferential hypertrophy of this paraspinal muscle in response to repetitive activation during fast bowling.