Creation of an asymmetrical gradient of back muscle activity and spinal stiffness during asymmetrical hip extension

Hu, Yaxi; Wong, Yu-lok.; Lu, William W.; Kawchuk, Gregory N.

doi:10.1016/j.clinbiomech.2009.07.013

Cited by 16 publications

(14 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…23,34 The difficulties of using this technique have now been solved by acquiring ultrasound videos of the LM muscle and holding an ultrasound transducer with an external mechanical arm. 18 Recording ultrasound videos from the rest state to a contracted state may be well suited for offline analysis. The ability to watch the videos offline may allow the examiner to select better images, which can enhance reliability and decrease time during the patient encounter.…”

Section: T T Resultsmentioning

confidence: 99%

“…21 Participants grasped a handheld weight, then raised the loaded arm off the examination table (with shoulders in 120° of abduction and the elbow in 90° of flexion), until their forearm touched a horizontal bar 5 cm above their original arm position (FIGURE 1). 18 They were instructed to maintain contact with the bar for 3 seconds. The handheld weight was designed to load the LM muscle to approximately 30% of maximum voluntary isometric contraction 21 according to individual body mass: participants with a body mass of less than 68.2 kg used a 0.68-kg weight, those whose body mass was between 68.2 and 90.9 kg used a 0.9-kg weight, and those with a body mass above 90.9 kg used a 1.36-kg weight.…”

Section: Methodsmentioning

confidence: 99%

“…41 The support system consisted of a multiarticulated arm that could be locked into position with compressed air, using a foot switch (SPIDER Limb Positioner; Tenet Medical Engineering, Calgary, Canada). 18 The angle between the transducer and the axis perpendicular to the participant's skin in the coronal plane was measured with a goniometer to guide the placement of the transducer in the second session.…”

Section: Data Collectionmentioning

confidence: 99%

“…To minimize the effect of respiration on LM muscle thickness in our experimental setup, participants were instructed to hold their breath at the end of normal exhalation during each CALT. The examiner evaluated the participants' breathing throughout the CALT practice and data collection to prevent participants from using a Valsalva maneuver, 18 which may affect lumbar biomechanics.…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Reliability of 2 Ultrasonic Imaging Analysis Methods in Quantifying Lumbar Multifidus Thickness

Wong¹,

Parent²,

Kawchuk³

2013

J Orthop Sports Phys Ther

View full text Add to dashboard Cite

The lumbar multifidus (LM) muscle plays a crucial role in maintaining segmental lumbar stability and preventing recurrence of low back pain (LBP). 17,27,42 Studies have shown that patients with acute or chronic LBP have localized LM atrophy and reduced voluntary LM muscle contraction ipsilateral to the side of symptoms.14,17,38 Unfortunately, the resolution of LBP is not accompanied with spontaneous recovery in the function and morphology of the LM muscle, unless appropriate exercises are prescribed. 16,27 To evaluate the function of the LM muscle and to monitor the progress of treatment, a costeffective, noninvasive clinical assessment tool is needed.Brightness-mode (B-mode) rehabilitative ultrasound imaging (RUSI) has been advocated as a valid noninvasive tool to evaluate the size and dynamic behavior of trunk muscles 40 and to provide real-time feedback to LBP patients during motor control training. 24,35 Research has demonstrated measurement agreement of LM muscle thickness by RUSI and by magnetic resonance imaging. 15Indwelling electromyography studies have also validated the correlation between the myoelectric activity of the LM and the change in geometry of the LM as measured by RUSI. 21,36 Clinically, the role of RUSI biofeedback in facilitating LM muscle recruitment in patients with LBP during back-stabilizing exercises has been demonstrated. 13,16,24,35,40 To measure LM muscle thickness T T STUDY DESIGN: Reliability study. T T OBJECTIVES:To compare the within-and between-day intrarater reliability of rehabilitative ultrasound imaging (RUSI) using static images (static RUSI) and video clips (video RUSI) to quantify multifidus muscle thickness at rest and while contracted. Secondary objectives were to compare the measurement precision of averaging multiple measures and to estimate reliability in individuals with and without low back pain (LBP). T T BACKGROUND:Although intrarater reliability of static RUSI in measuring multifidus thickness has been established, using video RUSI may improve reliability estimates, as it allows examiners to select the optimal image from a video clip. Further, multiple measurements and LBP status may affect RUSI reliability estimates. T T METHODS:Static RUSI and video RUSI were used to quantify multifidus muscle thickness at rest and during contraction and percent thickness change in 27 volunteers (13 without LBP and 14 with LBP). Three static RUSI images and 3 video RUSI video clips were collected in each of 2 sessions 1 to 4 days apart. Reliability and precision were assessed using intraclass correlation coefficients, standard error of measurement, minimal detectable change, bias, and 95% limits of agreement. T T RESULTS:Using an average of 2 measures yielded optimal measurement precision for static RUSI and video RUSI. Based on the average of 2 measures obtained under the same circumstance, there was no significant difference in the reliability estimates between static RUSI and video RUSI across all testing conditions. Reliability point estimates (intraclass correlation co...

show abstract

Section: T T Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Data Collectionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Reliability of 2 Ultrasonic Imaging Analysis Methods in Quantifying Lumbar Multifidus Thickness

Wong¹,

Parent²,

Kawchuk³

2013

J Orthop Sports Phys Ther

View full text Add to dashboard Cite

show abstract

“…Likewise, Owens et al [47] used the posterior‐to‐anterior spinal stiffness device to measure the baseline segmental lumbar stiffness from the L1 to L5 level of 173 patients with LBP, and found no significant bivariate correlation between PA lumbar stiffness and severity/chronicity of LBP before spinal manipulation. Unfortunately, this finding might have been affected by the inconsistent manual loading parameters (eg, loading speed) during the mechanically‐assisted spinal stiffness tests [72].…”

Section: Relation Between Segmental Spinal Stiffness and Lbpmentioning

confidence: 99%