Jean-Pierre Dumas

Validity and Between-Day Reliability of the Cervical Range of Motion (CROM) Device

STUDY DESIGN Clinical measurement, validity and intrarater reliability study. OBJECTIVES (1) To confirm the validity and assess between-day test-retest reliability of cervical spine motion measurements made with the cervical range of motion (CROM) device in flexion, extension, bilateral rotation, and bilateral side flexion; (2) to provide meaningful information to clinicians about the standard error of measurement and the minimal detectable change for the CROM device. BACKGROUND Range of motion is a common outcome measure used in the assessment of the cervical spine. The CROM device is one of the tools used to measure cervical range of motion in the clinical setting. However, its psychometric properties are not well established, especially for measurements taken on separate days. METHODS Quasi-experimental design with 1 group comparison. Twenty healthy adults (9 men and 11 women) participated in this study. Cervical range of motion was simultaneously recorded with the CROM device and the Fastrak motion analysis system for all 6 cervical movements mentioned above. The CROM device was placed on the participants head consistent with standard clinical procedures. Two Fastrak sensors were positioned with 1 on the forehead and 1 over the spinous process of the T6 vertebra. Test-retest reliability of measurements made with the CROM device was assessed, as well as its standard error of measurement and minimal detectable change, with measures taken on 2 separate days spaced 48 hours apart. RESULTS Values obtained by the 2 measuring devices yielded Pearson correlation coefficients ranging between 0.93 and 0.98. Test-retest reliability of measurements of cervical range of motion using the CROM was found to be good, with ICCs ranging between 0.89 and 0.98. The standard errors of measurement across the 6 movements ranged from 1.6 degrees to 2.8 degrees and the minimal detectable changes across the 6 movements ranged from 3.6 degrees to 6.5 degrees . CONCLUSIONS The measurements made with the CROM were shown to be reliable in all movement directions. J Orthop Sports Phys Ther 2010;40(5):318-323, Epub 12 March 2010. doi:10.2519/jospt.2010.3180.

Relationships between pain thresholds, catastrophizing and gender in acute whiplash injury

The mechanisms underlying sensory hypersensitivity (SH) in acute whiplash associated disorders (WAD) are not well understood. We examined the extent of the relationships between the sensory measures of pressure pain threshold (PPT) and cold pain threshold (CPT), catastrophizing, pain and disability levels and gender in acute WAD. Thirty-seven subjects reporting neck pain following a motor vehicle accident were examined within five weeks post-injury. Measures of neck pain and disability (Neck Disability Index, NDI) and catastrophizing (Pain Catastrophizing Scale, PCS) were taken. CPT was assessed in the cervical spine and PPTs were assessed in the cervical spine (PPTcx) and at a remote site (PPTdistal). CPT and PCS were moderately correlated (r=0.46; p < 0.01); however there were no significant relationships between PPT (cervical and distal) and PCS. Both CPT (r=0.55, p < 0.01) and PPTcx (r=-0.42, p < 0.01) were significantly correlated with NDI but PPTdistal was not (r=-0.08, p=0.65). Finally, gender modulated the relationships between sensory measures, catastrophizing, and pain and disability levels. In conclusion, subjects with higher levels of catastrophizing presented with sensory hypersensitivity to cold stimuli in the acute phase of whiplash. Differences between genders are in accordance with the growing body of evidence suggesting that the relationships between some psychological factors and injury-related symptoms are modulated by gender.

A triaxial dynamometer to monitor lateral bending and axial rotation moments during static trunk extension efforts

OBJECTIVE The purpose of the study was to describe a new static triaxial dynamometer designed to monitor the lateral bending and axial rotation moments during trunk extension efforts. BACKGROUND Most studies on back muscle function using electromyographic spectral analysis have not controlled moments produced about the three orthopaedic axes during trunk extension efforts. Criteria to control lateral bending and axial rotation moments during extension efforts have not been proposed in the literature. METHODS Fourteen healthy subjects performed three trunk extension ramp contractions (0-100% of the maximal voluntary contraction). Triaxial L5/S1 moments at 20%, 40%, 60% and 80% of the maximal voluntary contraction in extension were extracted. RESULTS During the extension efforts, the lateral bending and axial rotation moments at L5/S1 increased significantly across the force levels and reached 6.2 Nm (SD: 6.6) and 6.1 Nm (SD: 4.5), respectively, at 80% of the maximal voluntary contraction. Tolerance limits were proposed to control these associated efforts in the context of the electromyographic analysis of back muscles. Relevance. Simultaneous measurement of lateral bending and axial rotation moments at L5/S1 during extension efforts might help to explain and control load sharing between back muscles during extension efforts.

Assessment and validation of prognostic models for poor functional recovery 12 months after whiplash injury: A multicentre inception cohort study

Summary A previously identified predictive model (disability, older age, cold pain thresholds, neck rotation movement, posttraumatic stress symptoms) demonstrates good accuracy to discriminate participants with moderate to severe disability at 12 months after whiplash injury. Abstract Uncertainty surrounds prognostic factors after whiplash injury. Previously we identified a prognostic model for 6‐month pain‐related disability in a cohort of 80 participants with acute whiplash. Predictors included initial disability, older age, decreased cold pain thresholds, decreased neck rotation movement, posttraumatic stress symptoms and decreased sympathetic vasoconstriction. The objective of this study was to externally validate this model. In a multicentre inception cohort study, 286 participants with acute whiplash (I, II or III) were assessed at <3 weeks and 12 months after injury. The Neck Disability Index (NDI) was the outcome. Observed and predicted NDI scores were generated using the published equation of the original model. Model discrimination between participants with no or mild disability from those with moderate to severe disability was examined by receiver operating characteristic curves. Initial NDI and cold pain threshold predicted current observed 12‐month NDI scores (r2 = 0.50, 95% confidence interval 0.42 to 0.58). There was a significant site effect, and the estimated marginal mean ± SE of 12‐month NDI for Iceland (27.6 ± 1.79%) was higher than the other 3 sites (Melbourne 11.2 ± 5.03%, Canada 16.4 ± 2.36%, Brisbane 16.8 ± 1.17%). After adjusting for site, age and Impact of Events Scale scores regained significance (r2 = 0.56, 95% confidence interval 0.48 to 0.64). The tested model was not precise in predicting NDI as a continuous variable. However, it found good accuracy to discriminate participants with moderate to severe disability at 12 months (area under the receiver operating characteristic curve 0.89 [95% confidence interval 0.84–0.94], P < .001) which is clinically useful.

Maximal Voluntary Isometric Neck Strength Deficits in Adults With Whiplash-Associated Disorders and Association With Pain and Fear of Movement

STUDY DESIGN Controlled laboratory study using a cross-sectional, repeated-measures design. OBJECTIVES To quantify maximal voluntary isometric neck forces in healthy subjects and individuals with whiplash-associated disorder (WAD), using an objective measurement system to evaluate the test-retest properties of these strength measurements and to assess the links between neck strength, pain, kinesiophobia, and catastrophizing in patients with WAD. BACKGROUND The prognosis of WAD is difficult to predict due to a lack of objective measurement methods and to our limited understanding of the role of psychological factors in the development of chronic WAD symptoms. METHODS AND MEASURES Fourteen subjects with chronic WAD grade I or II and an age-matched, healthy group (n = 28) participated in this study. Cervical strength was measured with the Multi-Cervical Unit (MCU) in 6 directions, and pain was measured with a visual analog scale. Individuals in the WAD group completed the Neck Disability Index (NDI), the Tampa Scale for Kinesiophobia (TSK), and the Pain Catastrophizing Scale (PCS). RESULTS Significant deficits in strength were observed for the individuals in the WAD group compared to the healthy group, particularly in extension, retraction, and left lateral flexion (P<.05). The MCU demonstrated good intratester reliability for the healthy group (ICC = 0.80-0.92) and the WAD group (ICC = 0.85-0.98), and small standard errors of measurement for both groups. No significant association was found between neck strength and NDI, TSK, and PCS. CONCLUSION The MCU demonstrated good test-retest properties for healthy subjects and individuals with WAD. Cervical strength was lower in individuals with WAD; however, the strength deficits were not clearly linked with psychological factors.

Reliability of Ultrasound Measures of the Transversus Abdominis: Effect of Task and Transducer Position

To assess the reliability of ultrasound (US) measures of the transversus abdominis (TrA) muscle in a sample of subjects with and without specific chronic low back pain and to test whether reliability is enhanced by using different abdominal muscle activation tasks, with use of a foam cube for US transducer stabilization or by averaging 3 measures on the same image.

The effects of an 8-week stabilization exercise program on lumbar movement sense in patients with low back pain

BackgroundLumbar stabilization exercises have gained popularity and credibility in patients with non-acute low back pain. Previous research provides more support to strength/resistance and coordination/stabilisation programs. Some authors also suggest adding strength/resistance training following motor control exercises. However, the effect of such a lumbar stabilization program on lumbar proprioception has never been tested so far. The present study investigated the effects of an 8-week stabilization exercise program on lumbar proprioception in patients with low back pain (LBP) and assessed the 8-week test-retest reliability of lumbar proprioception in control subjects.MethodsLumbar proprioception was measured before and after an 8-week lumbar stabilization exercise program for patients with LBP. Control subjects participated in the same protocol but received no treatment.ResultsThe lumbar proprioception measure showed moderate reliability. Patients with LBP and control subjects demonstrated no differences in lumbar proprioception at baseline. Participants from both groups showed better proprioception following the 8-week interval, demonstrating the presence of learning between testing days.ConclusionsThe improvement of lumbar proprioception seen in both groups was ascribed to motor learning of the test itself. The effect of lumbar stabilization exercises on lumbar proprioception remains unknown because the LBP group did not show lumbar proprioception impairments.

Ultrasound Measures of the Lumbar Multifidus: Effect of Task and Transducer Position on Reliability

To (1) assess the intra‐ and inter‐rater reliability of different ultrasound (US) measures of the lumbar multifidus muscle in subjects with and without chronic low back pain and (2) test 3 different ways to enhance reliability, that is, by testing different tasks, using a template, and averaging trials within or between days.

Influence of test position on neck muscle fatigue in healthy controls

BACKGROUND It has been suggested that increased fatigue of neck muscles could be related to neck pain. However, studies on the matter present contradicting results which could be explained by the different test positions used. PURPOSE The purpose of this study was to investigate the influence of test position on muscle fatigue of neck flexor and extensor muscles in healthy controls. METHODS Twenty-five women without neck pain sustained neck flexion and neck extension isometric contractions at 25% and 75% of their maximal voluntary contraction (MVC) in two test positions: sitting and supine lying. Using surface electromyography, the change over time of the median frequency of the power spectrum (MDF slope) of the myoelectric signal of the sternocleidomastoid and splenius capitis muscles was measured and compared between both positions. RESULTS At 75% MVC, splenius capitis muscles presented higher fatigue in lying compared to sitting, while sternocleidomastoid demonstrated no difference between positions. No statistically significant effect of test position was found at 25% MVC for both sternocleidomastoid and splenius capitis muscles as they generally did not present myoelectric manifestations of fatigue. CONCLUSION These results underline the need to standardise the test position when investigating neck muscle fatigue, especially for neck extensors at high loads.

The Effects of an 8-Week Stabilization Exercise Program on Lumbar Multifidus Muscle Thickness and Activation as Measured With Ultrasound Imaging in Patients With Low Back Pain: An Exploratory Study

Lumbar stabilization exercise programs (LSEP) produce positive effects on clinical outcomes, but the underlying mechanisms remain relatively unexplored. Psychological and neuromuscular mechanisms can be involved, such as a better activation of the lumbar multifidus, which represents one possibility.