STUDY DESIGN: A single-blinded, pretreatment-posttreatment assessment. OBJECTIVES: To investigate, using ultrasound imaging, the cross-sectional area (CSA) of the lumbar multifidus muscle at 4 vertebral levels (L2, L3, L4, L5) in elite cricketers with and without low back pain (LBP) and (2) to document the effect of a staged stabilization training program on multifidus muscle CSA. BACKGROUND: Despite high fitness levels and often intensive strength training programs, athletes still suffer LBP. The incidence of LBP among Australian cricketers is 8% and as high as 14% among fast bowlers. Previous researchers have found that the multifidus muscle contributes to segmental stability of the lumbopelvic region; however, the CSA of this muscle has not been previously assessed in elite cricketers. METHODS AND MEASURES: CSAs of the multifidus muscles were assessed at rest on the left and right sides for 4 vertebral levels at the start and completion of a 13-week cricket training camp. Participants who reported current or previous LBP were placed in a rehabilitation group. The stabilization program involved voluntary contraction of the multifidus, transversus abdominis, and pelvic floor muscles, with real-time feedback from rehabilitative ultrasound imaging (RUSI), progressed from non-weight-bearing to weight-bearing positions and movement training. Pain scores (using a visual analogue scale) were also collected from those with LBP. RESULTS: The CSAs of the multifidus muscles at the L5 vertebral level increased for the 7 cricketers with LBP who received the stabilization training, compared with the 14 cricketers without LBP who did not receive rehabilitation (P = .004). In addition, the amount of muscle asymmetry among those with LBP significantly decreased (P = .029) and became comparable to cricketers without LBP. These effects were not evident for the L2, L3, and L4 vertebral levels. There was also a 50% decrease in the mean reported pain level among the cricketers with LBP. CONCLUSION: Multifidus muscle atrophy can exist in highly active, elite athletes with LBP. Specific retraining resulted in an improvement in multifidus muscle CSA and this was concomitant with a decrease in pain. LEVEL OF EVIDENCE: Therapy, level 2b.

J Orthop Sports Phys Ther. 2008;38(3):101-108, published online 7 December 2007. doi:10.2519/jospt.2008.2658

KEY WORDS: asymmetry, low back/lumbar spine rehabilitation, rehabilitative ultrasound imaging, therapeutic exercise, ultrasound imaging

STUDY DESIGN: Test-retest intrarater reliability study. OBJECTIVE: To examine reliability of abdominal musculature measurements across a broad range of conditions for a physical therapist newly trained in assessment using rehabilitative ultrasound imaging (RUSI). BACKGROUND: RUSI has previously been used to assess abdominal muscle function during a drawing-in maneuver of the anterior abdominal wall, and measurements conducted by an experienced assessor have been validated by comparison with magnetic resonance imaging. Few studies have examined the reliability of less experienced operators, and only in isolated measurement conditions. METHODS AND MEASURES: Nineteen subjects (11 female, 8 male) without a history of low back pain performed the abdominal drawing-in maneuver in a supine hook-lying position. RUSI was used bilaterally to assess the thickness of the internal oblique (IO) and transversus abdominis (TrA) muscles at rest and on contraction as well as changes in the length of the TrA muscle (indicated by slide of the anterior abdominal fascia). The reliability of a novice rater who received 8 hours of training was examined (a) across 3 measurements of the same ultrasound image, (b) across 3 separate ultrasound images (averaged for days and sides of abdomen), and (c) across 2 days (averaged for images and sides). RESULTS: Reliability of assessing muscle thickness was very high across 3 measurements of the same image (intrarater correlation coefficients [ICC_3,1] were all greater than 0.97), fair to high across 3 images (ICC_3,4 = 0.62-0.82), and fair to high across 2 days (ICC_3,6 = 0.63-0.85). Reliability of measuring the slide of the anterior abdominal fascia was very high across measurements from the same image (ICC_3,1 = 0.98) but very low across images (ICC_3,4 = 0.44) and across 2 days (ICC_3,6 = 0.36). CONCLUSIONS: High reliability of a novice rater was demonstrated for some measurement conditions. Measures of reliability for recapturing the image and repetition across days ranged from low to high. Inconsistencies in the pattern of results suggest that for a novice assessor using RUSI, training should be performed and reliability assessed for each abdominal muscle and measurement condition intended to be used for research and clinical practice.

J Orthop Sports Phys Ther. 2007:37(8):480-486; published online 30 May 2007. doi:10.2519/jospt.2007.2416

KEY WORDS: internal oblique muscle, real-time ultrasound imaging, sonography, transversus abdominis muscle

J Orthop Sports Phys Ther. 2007;37(10):608-612, published online 29 May 2007. doi:10.2519/jospt.2007.2418

KEY WORDS: back muscles, lumbar spine, muscle assessment, repeatability, ultrasonography