Alan D. Hough

M-mode ultrasound: a reliable measure of transversus abdominis thickness?

OBJECTIVE The purpose of this study was to establish a reliable method for measuring transversus abdominis thickness in asymptomatic human subjects in supine lying, standing and walking. DESIGN AND METHODS This was a single operator reliability study using ultrasound imaging to measure 22 subjects on three separate occasions. A purpose built high-density foam reinforced belt was used to house and position the transducer over the mid-point of the transversus abdominis. Each subject was imaged in supine, standing, and treadmill walking at 3 kph. Intraclass correlation coefficients and standard error of measurement analysis were used to measure the data. RESULTS The correlation coefficient data analysis resulted in intraclass correlation coefficients of 0.94 (standard error of measurement 0.35) in supine lying, 0.88 (0.66) in standing and 0.88 (0.56) in walking. CONCLUSION The method described is a reliable tool for measuring changes in thickness of transversus abdominis in supine lying, standing and walking. RELEVANCE This procedure has the potential to detect dysfunctional changes in abdominal muscle activity for patients with low back pain in a functional setting.

Measurement of abdominal muscle thickness using M-mode ultrasound imaging during functional activities

Ultrasound imaging has been previously utilized in the measurement of muscle thickness and cross-sectional area in research studies, and advocated as a clinical biofeedback tool in the rehabilitation of transversus abdominis function following episodes of low back pain. This paper describes how the thickness of the abdominal muscles can be quantified with a new measurement technique using M-mode ultrasound. The technique uses a custom-made transducer holder that facilitates measurement of muscle thickness changes during functional activity. Limitations of the technique and potential future applications are discussed. The M-mode ultrasound technique may provide an effective method for the non-invasive measurement of abdominal muscle thickness during functional activities.

Peripheral Nerve Motion Measurement with Spectral Doppler Sonography: A Reliability Study

This study evaluates single operator test-retest reliability of spectral Doppler ultrasound measurement of median nerve excursion during wrist extension. Longitudinal motion of the median nerve was measured at the elbow on three occasions in both upper limbs of 16 healthy subjects using a standard colour Doppler ultrasound system. The mean of the three maximum velocity time integrals was calculated from the spectral Doppler sonogram of each test. Analysis of data with intraclass correlation coeffcient indicated a high degree of repeatability (0.92). Spectral Doppler ultrasound may provide a valuable method for measurement of peripheral nerve motion and may have a role in the clinical assessment of entrapment syndromes.

A new, comprehensive normative database of lumbar spine ranges of motion

Aims and objectives: To generate gender-specific and broadly based agerelated indices for normative lumbar ranges of motion for all planes of movement. Design: This was a repeated measures prospective study of spinal range of motion in a sample of volunteer subjects utilizing a portable modified CA6000 Spine Motion Analyzer (Orthopedic Systems Inc., Union City, CA, USA). Setting: Data collection was carried out in a variety of community locations including fire, police and ambulance stations, offices and community centres. Subjects: A total of 405 asymptomatic subjects (196 female, 209 male) were recruited, aged 16–90 years, from sedentary, mixed and physically demanding occupations. Methodology: Indices of lumbar spine ranges of motion were measured in standing following a standardized protocol for sagittal flexion/extension, coronal lateral flexion and horizontal axial rotation movements. Results: Male and female normative flexion ranges declined by approximately 40% (72–40 degrees) across the age spectrum. Extension declined the greatest, by approximately 76% (29–6 degrees) overall. In lateral flexion male and female ranges declined approximately 43% (29–15 degrees) in each direction (total 58–30 degrees). In axial rotation no age-related decline was observed and ranges of motion remained at approximately 7 degrees in each direction (total 14 degrees) across all the ages of the subject group. Conclusions: Data have been generated that provide comprehensive, gender-specific, broadly based and age-related indices for normative lumbar ranges of motion in all planes of movement. These are applicable to individuals throughout adult life, from adolescence through to old age.

Repeatability of measuring sciatic nerve excursion during a modified passive straight leg raise test with ultrasound imaging.

The purpose of this study was to establish the reliability of a frame-by-frame cross correlation method of assessing longitudinal sciatic nerve excursion motion using real time ultrasound imaging during a modified passive straight leg raise (SLR) test. Eighteen asymptomatic participants (age range 19-68 years) lay on their sides on a purpose made jig and the sciatic nerve in the posterior thigh was imaged during knee extension at 30° and then 60° of hip flexion (HF). Participants were re-tested ≥48 h later. The ultrasound images were analysed off-line using cross correlation software. Results demonstrated excellent repeatability of in vivo sciatic nerve excursion during a modified SLR (HF30° ICC 0.92, CI 0.79-0.97, SEM 0.69; HF60° ICC 0.96, CI 0.89-0.99, SEM 0.87). The authors also identify points of good practise to ensure an accurate as possible measurement of nerve excursion using this method. These include breaking down larger movements into sub-components, visually tracking the moving nerve during the tracking procedure, and ensuring the optimal image is captured prior to analysis. The use of ultrasound imaging in lower limb nerve dysfunction will enhance the understanding of how nerves move in vivo during neurodynamic testing, as well as being able to identify possible alteration to nerve movements in patients with neuropathic pain states.

Effects of Pilates-Based Core Stability Training in Ambulant People With Multiple Sclerosis: Multicenter, Assessor-Blinded, Randomized Controlled Trial.

Background Pilates exercise is often undertaken by people with multiple sclerosis (MS) who have balance and mobility difficulties. Objectives The primary aim of the study was to compare the effects of 12 weeks of Pilates exercises with relaxation on balance and mobility. Secondary aims were: (1) to compare standardized exercises with relaxation and (2) to compare Pilates exercises with standardized exercises. Methods A multicenter, assessor-blinded, randomized controlled trial was conducted. Participants with Expanded Disability Status Scale scores of 4.0 to 6.5 were randomly allocated to groups receiving 12 weeks of Pilates exercises, standardized exercises, or relaxation. Assessments were undertaken at baseline and weeks 12 and 16 (primary outcome measure: 10-Meter Timed Walk Test [10MTW]). Results One hundred participants (mean age=54 years, 74% female) were randomized to study groups. Six participants relapsed (withdrew from the study), leaving 94 participants for intention-to-treat analysis. There was no significant difference in mean 10MTW measurements between the Pilates and relaxation groups. At 12 weeks, there was a mean reduction of 4.2 seconds for the standardized exercise group compared with the relaxation group (95% confidence interval [relaxation group minus standardized exercise group measurements]=0.0, 8.4) and a mean reduction of 3.7 seconds for the Pilates group compared with the standardized exercise group (95% confidence interval [Pilates group minus standardized exercise group measurements]=−0.4 to 7.8). At 16 weeks, mean 10MTW times for the standardized exercise group remained quicker than those for the Pilates and relaxation groups, although the differences were nonsignificant. There were no significant differences between the Pilates and relaxation groups for any secondary outcome measure. Limitations In this study, therapists were limited to a standardized basket of exercises that may have affected the study outcomes. Furthermore, choosing measures such as posturography to assess balance, accelerometry to assess walking, or a specific trunk assessment scale might have been more responsive in detecting changes in outcome. Conclusion Participants did not improve significantly, either in the short term or at the 4-week follow-up, on the 10MTW after 12 weeks of Pilates exercises compared with 12 weeks of relaxation.

Sciatic nerve excursion during a modified passive straight leg raise test in asymptomatic participants and participants with spinally referred leg pain

BACKGROUND Minimal data exists on in-vivo sciatic nerve motion during straight leg raise (SLR), particularly in symptomatic participants. Such data could help clinicians to better understand nerve mechanic changes following nerve dysfunction. DESIGN Cross-sectional, controlled laboratory study. OBJECTIVES To investigate whether individuals with spinally referred leg pain have different nerve excursion patterns compared to healthy participants. METHOD The sciatic nerve was scanned using ultrasound imaging in the posterior thigh in asymptomatic participants, and individuals with spinally referred leg pain sub-grouped into somatic pain, radicular pain or radiculopathy. Nerve excursion was measured in transverse and longitudinal planes during a side-lying modified SLR. The ultrasound data was analysed off-line using cross correlation software. Longitudinal plane data was collected from 16 asymptomatic and 60 symptomatic participants and transverse plane data from 16 asymptomatic and 56 symptomatic participants. RESULTS There was no significant difference in longitudinal nerve excursion between the 4 groups. The direction of transverse plane motion altered between groups. These varied movements may be related to protective muscle activation between the groups, although this is speculative at present. CONCLUSION Longitudinal sciatic nerve excursion at the posterior thigh during a modified SLR is not different between asymptomatic participants and those with spinally referred leg pain. Transverse plane movement appears to be more varied. This may suggest that in individuals with nerve root pain, there is no restriction in nerve excursion. However, as it was not possible to measure excursion at the nerve root, more research is needed to confirm these findings.

Deep abdominal muscle activity following supratentorial stroke

This study assessed the level and symmetry of deep abdominal muscle activation following a supratentorial stroke during a modified hip flexion task. Movement-related activation levels in the transversus abdominus (TrA) and internal oblique (IO) were investigated in people with a subacute (<3.25months) supratentorial stroke (n=11) and a matched control group (n=11). Electromyographic activity in TrA and IO were recorded using fine wires inserted under ultrasound guidance while participants performed a standardised head lift or unilateral hip flexion. During head lift there was no significant difference in the amplitude of activation ipsi- and contra-lateral to the stroke or between groups. During unilateral hip flexion the TrA and IO were activated more on both sides when moving the paretic leg. In the control group muscle activity was modulated by task with activity being higher ipsilateral to the moving leg; in contrast in the stroke group IO muscle activity tended to be higher on the non-paretic side irrespective of moving limb. Greater TrA and IO muscle activity during hip flexion of the paretic leg may represent compensatory activity that acts to facilitate activation of the paretic hip flexors and/or the presence of overflow.

Test-Retest Reliability of Measuring the Vertebral Arterial Blood Flow Velocity in People With Cervicogenic Dizziness

Objectives: The purpose of this study was to determine the within‐session and between‐sessions reliability of measuring the vertebral artery blood flow velocities in people with cervicogenic dizziness using Doppler ultrasound at both upper and lower cervical levels. Methods: Outcome measures were taken on 2 occasions 3 weeks apart with no active treatment provided in between the assessments on 12 participants. Pulsed‐wave Doppler ultrasound was used to quantify time‐averaged mean velocities through the vertebral artery at upper cervical (C0‐1) and lower cervical vertebrae (C5‐6). The clinical outcome measures were also recorded in people with cervicogenic dizziness. The intraclass correlation coefficient (ICC) was used to determine the within‐session and between‐session repeatability. Paired t test was used to determine the differences in the time‐averaged mean velocities of blood flow at the same site of the vertebral artery and the clinical outcome measures in 2 sessions 3 weeks apart. Results: In people with cervicogenic dizziness, there was no significant change in both clinical outcome measures and the time‐averaged mean velocities when the patients were measured 3 weeks apart (P > .05). This study identified good within‐session (ICC: 0.903‐0.967) and between‐session (ICC: 0.922‐0.984) repeatability in measuring the vertical blood flow velocities in patients with cervicogenic dizziness when the clinical outcome measures were unchanged. Conclusions: This study supports the use of Doppler ultrasound to identify changes in mean vertebral arterial blood flow velocities before and after intervention in people with cervicogenic dizziness in future studies.

Superficial warming and cooling of the leg affects walking speed and neuromuscular impairments in people with spastic paraparesis.

BACKGROUND People with hereditary and spontaneous spastic paraparesis (HSSP) report that their legs are stiffer and walking is slower when their legs are cold. OBJECTIVES This study explored the effects of prolonged superficial cooling and warming of the lower leg on walking speed and local measures of neuromuscular impairments. METHODS This was a randomised pre- and post-intervention study of 22 HSSP participants and 19 matched healthy controls. On 2 separate occasions, one lower leg was cooled or warmed. Measurements included walking speed and measures of lower limb impairment: ankle movement, passive muscle stiffness, spasticity (stretch reflex size), amplitude and rate of force generation in dorsi- and plantarflexors and central and peripheral nerve conduction time/velocity. RESULTS For both participants and controls, cooling decreased walking speed, especially for HSSP participants. For both groups, cooling decreased the dorsiflexor rate and amplitude of force generation and peripheral nerve conduction velocity and increased spasticity. Warming increased dorsiflexor rate of force generation and nerve conduction velocity and decreased spasticity. CONCLUSIONS Superficial cooling significantly reduced walking speed for people with HSSP. Temperature changes were associated with changes in neuromuscular impairments for both people with spastic paraparesis and controls. This study does not support the use of localised cooling in rehabilitation for people with spastic paraparesis as reported in other neurological conditions. Rehabilitation interventions that help prevent heat loss (insulation) or improve limb temperature via passive or active means, particularly when the legs and/or environment are cool, may benefit people with spastic paraparesis.