Reliability and Precision of Sonography of the Lumbar Multifidus and Transversus Abdominis During Dynamic Activities.
OBJECTIVE
To determine the intrarater reliability and precision of lumbar multifidus and transversus abdominis thickness measurements using freehand sonography in a range of static and dynamic conditions.


METHODS
Fifteen asymptomatic participants performed a range of exercises while sonography was used to measure absolute muscle thickness and changes in muscle thickness from rest. Exercise conditions included the abdominal drawing-in maneuver, active straight leg raise, contralateral arm lift, both unloaded and loaded, treadmill walking, and using the Functional Readaptive Exercise Device. Intraday and interday reliability was assessed by intraclass correlation coefficients, and the standard error of measurement was used to assess measurement precision.


RESULTS
Good to excellent reliability was achieved for absolute transversus abdominis and lumbar multifidus thickness in all conditions. Measurement precision for absolute lumbar multifidus thickness was ≤2.8 mm for the unloaded contralateral arm lift, ≤1.8 mm for the loaded contralateral arm lift, ≤3.1 mm for treadmill walking, and ≤3.8 mm for the Functional Readaptive Exercise Device; for absolute transversus abdominis thickness, precision was ≤0.6 mm for the abdominal drawing-in maneuver, ≤0.5 mm for the active straight leg raise, ≤0.7 mm for treadmill walking, and ≤0.5 mm for the Functional Readaptive Exercise Device. Good to excellent reliability was achieved for relative transversus abdominis and lumbar multifidus thickness in all conditions. Measurement precision for relative lumbar multifidus thickness was ≤3.7% for the unloaded contralateral arm lift, ≤3.8% for the loaded contralateral arm lift, ≤6.3% for treadmill walking, and ≤7.6% for the Functional Readaptive Exercise Device; for relative transversus abdominis thickness, precision was ≤13.6% for the abdominal drawing-in maneuver, ≤6.9% for the active straight leg raise, ≤11.1% for treadmill walking, and ≤7.2% for the Functional Readaptive Exercise Device.


CONCLUSIONS
Acceptable reliability and precision of measurement is achieved for absolute and relative measures of deep spinal muscle thickness using freehand sonography in relatively static and dynamic exercises.
Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, England.
Karl C
KC
Gibbon
Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, England.
Dorothee
D
Debuse
Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, England.
Angela
A
Hibbs
Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, England.
Nick
N
Caplan
D000009:Abdominal Muscles / Q000033:anatomy & histology* / Q000502:physiology*; D000328:Adult; D064131:Back Muscles / Q000033:anatomy & histology* / Q000502:physiology*; D001837:Body Weights and Measures / Q000379:methods; D015444:Exercise; D005260:Female; D006801:Humans; D008161:Lumbosacral Region / Q000033:anatomy & histology / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D015588:Observer Variation; D012016:Reference Values; D015203:Reproducibility of Results; D014463:Ultrasonography
musculoskeletal ultrasound; precision; reliability; sonography; spinal muscles