Relationships between isoinertial lumbar dynamometry parameters and demographic parameters in chronic low back pain patients

Abstract

IntroductionInterest in developing isoinertial measurement techniques to evaluate the low back muscle function in patients with chronic low back pain has increased during the last few years. Patient performance is compared with standards estimated for healthy persons in order to gain insight into the low back muscle function. A problem inherent in muscle performance testing, however, is the large degree of intersubject variability. The absolute magnitude of force or velocity produced by individuals will vary according to different populations, depending on various factors, e.g. gender, age, weight and height. For example, the force exerted by a 60-year-old woman will be different from that expected for a 20-year-old man. The problem facing the clinician is interpretation of the obtained muscle performance. One way to handle this large intersubject variabilAbstract The purpose of this study was to investigate which demographic parameters are most important in relation to lumbar dynamometry performance in patients with chronic low back pain (LBP). Fortyfive chronic LBP patients participated in this study. Gender, age, weight and height were determined and a lumbar dynamometry measurement was carried out, using the Isostation B200. Student's t-test, ANOVA techniques and correlation coefficients were used to investigate the relationships between each demographic parameter and lumbar dynamometry performance. Stepwise multiple linear regression analyses were performed afterwards to determine which demographic parameters are most important in relation to lumbar dynamometry performance. Results indicate significant relationships (1) between gender, height, weight and all lumbar dynamometry parameters and (2) between age and three of the six isometric torque parameters. No significant relationship was found between age and maximum velocity parameters. Results of the stepwise multiple linear regression analyses show that the demographic parameters explain 27-47% of the variance in maximum isometric strength parameters and 19-25% of the variance in maximum velocity parameters. Gender is the most important demographic parameter, being related to nearly all maximum isometric torque parameters (percentage explained variance 6-37%) and height is the only important demographic parameter related to the velocity parameters (percentage explained variance 19-25%). Weight and age account for only a small amount of variance in lumbar dynamometry parameters (percentage explained variance 5-7%), meaning that these parameters are non-relevant predictors.

Course and prognosis of recovery for chronic non-specific low back pain: design, therapy program and baseline data of a prospective cohort study

“…The prognostic factors include: a) demographic characteristics such as educational level, marital status, weight, alcohol, smoking and drug consumption; b) clinical status such as body mass index (BMI), pain below the knee, cause and duration of complaints, previous rehabilitation, degree of fatigue [ 31 ], low back pain intensity (VAS) [ 32 , 33 ] and disability (QBPDS). [ 34 , 35 ]; c) psychological characteristics such as fear avoidance (TSK) [ 36 - 42 ] and quality of life (SF-36) [ 43 ]; d) work-related characteristics such as employment benefits and work participation in relation to back complaints, and e) physical characteristics such as the mobility of lumbar pelvic rhythm (video registration) [ 44 ], strength (B-200 isostation) [ 45 , 46 ] and activities of daily living (ADL) consisting of walking, sitting, bicycling and lying. Figure 1 shows the physical tests that are measured at intake, evaluated at the end of therapy, and at 5 months after start of therapy.…”

Characteristic dynamic differences between healthy and low back pain subjects

“…19 Our healthy subjects (NS group) are di erent in respect to their age (both sexes) and weight (females) from the symptomatic patients (LBP group), Table 1. Most of the subjects were volunteers from the sta , younger and keeping in shape, while the patients were of older ages and less active.…”