Facilitating Effects of Fast and Slope Walking on Paraspinal Muscles

OBJECTIVE: To quantify the activation of the paraspinalis muscles (multifidus and erector spinae) at different walking velocities and slope with surface electromyography. METHODS: This study was a prospective experimental study involving ten healthy male participants. Surface electrodes were placed over the multifidus and erector spinae muscles at the L5 and L3 level. After the electrode was placed at the lumbar paraspinalis muscles, electromyography signals were recorded over 20 seconds. Data were collected three times during the walking exercise at a 0degrees gradient with the speed from 3 to 6 km/hr. At 7degrees gradient and 15degrees gradient, data were also collected three times but a walking speed of 4 km/hr. The area under the curve was calculated for quantitative measurement of muscle activation. RESULTS: While the muscle activation was increased at higher walking velocities at the L5 and L3 levels of the multifidus, the erector spinae muscle activation did not show any change at higher walking velocities. At L3 level of the multifidus and erector spine muscles, the muscle activation was significantly increased in 15degrees gradient compared to those seen in at 0degrees gradient. At L5 level, the multifidus and erector spinae muscle activation in 0degrees gradient was not significantly different from that those seen in 7degrees or 15degrees gradient. CONCLUSION: Fast walking exercise activates lumbar multifidus muscles more than the slow walking exercise. Also, the mid lumbar muscles are comparatively more activated than low lumbar muscles when the walking slope increases.

Reliability and Applicability of the Bayley Scale of Infant Development-II for Children With Cerebral Palsy

OBJECTIVE: To obtain reliability and applicability of the Korean version Bayley Scale of Infant Development-II (BSID-II) in evaluating the developmental status of children with cerebral palsy (CP). METHODS: The inter-rater reliability of BSID-II scores from 68 children with CP (46 boys and 22 girls; mean age, 32.54+/-16.76 months; age range, 4 to 78 months) was evaluated by 10 pediatric occupational therapists. Patients were classified in several ways according to age group, typology, and the severity of motor impairment by the level of the Gross Motor Function Classification System (GMFCS). The measures were performed by video analysis, and the results of intraclass correlation (ICC) were obtained for each of the above classifications. To evaluate the clinical applicability of BSID-II for CP, its correlation with the Gross Motor Function Measure (GMFM), which has been known as the standard motor assessment for CP, was investigated. RESULTS: ICC was 0.99 for the Mental scale and 0.98 for the Motor scale in all subjects. The values of ICC ranged from 0.92 to 0.99 for each age group, 0.93 to 0.99 for each typology, and 0.99 to 1.00 for each GMFCS level. A strong positive correlation was found between the BSID-II Motor raw score and the GMFM total score (r=0.84, p<0.001), and a moderate correlation was observed between the BSID-II Mental raw score and the GMFM total score (r=0.65, p<0.001). CONCLUSION: The Korean version of BSID-II is a reliable tool to measure the functional status of children with CP. The raw scores of BSID-II showed a great correlation with GMFM, indicating validity of this measure for children with CP on clinical basis.

Association between Cross-sectional Areas of Lumbar Muscles on Magnetic Resonance Imaging and Chronicity of Low Back Pain

OBJECTIVE: To investigate the prognostic value of cross-sectional areas (CSA) of paraspinal (multifidus and erector spinae) and psoas muscles on magnetic resonance imaging (MRI) in chronicity of low back pain. METHOD: Thirty-eight subjects who visited our hospital for acute low back pain were enrolled. Review of their medical records and telephone interviews were done. Subjects were divided into two groups; chronic back pain group (CBP) and a group showing improvement within 6 months after onset of pain (IBP). The CSA of paraspinal and psoas muscles were obtained at the level of the lower margin of L3 and L5 vertebrae using MRI. RESULTS: CSA of erector spinae muscle and the proportion of the area to lumbar muscles (paraspinal and psoas muscles) at L5 level in the CBP group were significantly smaller than that of the IBP group (p0.05). CSA of psoas muscle at L5 level and all values measured at L3 level were not significantly different between the groups (p>0.05). CONCLUSION: CSA of erector spinae muscle at the lower lumbar level and the proportion of the area to the lumbar muscles at the L5 level can be considered to be prognostic factors of chronicity of low back pain.