The Reliability of Ultrasound Imaging in measuring the Thickness of Lumbar Multifidus Muscle in Gymnastics Athletes with Sway-Back and Normal Posture

Sway-Back Posture (SBP) is one of the most common poor postures especially among the female gymnastics athletes. It can result in multifidus muscles insufficiency and inability to support the spinal column. The aim of this study was to evaluate the intra-rater reliability of ultrasound imaging to measure the thickness of lumbar multifidus (LMM) muscle at different lumbar levels during both states of muscle at rest and contraction.

The subjects of this study were 10 females’ gymnastics athletes among whom five had sway back posture. To have the posture assessed the plumb line and grid paper were used. The LMM thicknesses of all lumbar segments were measured thrice (with 1houre minutes interval) by the same examiner in both rest and contraction position simultaneous with arm lifts done by a real time Ultrasonography device.

The results of the relative and the absolute reliability of LMM thickness measurements at the state of rests were 0.97 < ICC < 0.99, 0.34 < SEM < 0.48 and 0.94 < MDC< 1.34 and at the state of contractions they were as: 0.95 < ICC < 0.98, 0.47< SEM < 0.71 and 1.31 < MDC< 1.98. The results of the Bland-Altman plotting indicated a good level of agreement between two measurements at all lumbar levels in both states of rest and contraction.

The results of this study indicated that the method of ultrasonography had a high level of reliability and accuracy to measure the thickness of LMM in both states of muscle at rest and contraction. The method is highly recommended in physiotherapy and rehabilitation assessments.