Effect of active limb movements on symptoms in patients with low back pain.

STUDY DESIGN: A descriptive, correlational study of patients with mechanical low back pain (LBP). OBJECTIVES: To assess the effect of active limb movements on symptoms in patients with LBP and to examine the relationship between symptoms with limb movements and select patient characteristics. BACKGROUND: Limb movements result in forces applied to the spine and, thus, may be important in the examination and treatment of patients with LBP. METHODS AND MEASURES: A total of 188 people with LBP, 84 men and 104 women, participated in a standardized examination. Six of the items required patients to move their limbs and note LBP symptoms as increased, remained the same, or decreased. The prevalence of various symptom responses with each limb movement test was calculated. Relationships between patient characteristics and reports of increased symptoms were examined with Cochran's linear trend statistic and the Spearman and Pearson correlation coefficients. Differences in characteristics of patients with and without increased symptoms were examined with chi2 test, Mann-Whitney U test, or Student's t test for independent groups. RESULTS: An increase in symptoms was reported by 149 patients with at least 1 of the limb movement tests, and 3 of the patients reported a decrease in symptoms. Across the patient sample, the mean number of limb movement tests for which symptoms were reported as increased was 2.30 +/- 1.64. Patients with an increase in symptoms reported higher average pain intensity the week prior to the examination (median = 2; range: 1-5) and higher functional disability (mean = 0.25; SD = 0.15) than those without a change in symptoms (pain intensity: median = 1; range: 0-2 and functional disability: mean = 0.16; SD = 0.12). The correlation between the number of increased symptoms and the person's average pain intensity was r = 0.23; the correlation with the functional disability score was r = 0.36. Patients with a history of LBP tended to report an increase in symptoms with more of the limb movement tests (mean = 3.5; SD = 1.40) than those without a previous history of LBP (mean = 2.0; SD = 1.11). CONCLUSIONS: Active limb movements performed during the examination primarily resulted in increased LBP symptoms. The presence and number of increased symptoms with the active limb movements was related to the patient's report of average pain intensity and functional disability. Tests of symptoms with active limb movements may provide insight into factors contributing to a LBP problem, as well as information to guide the treatment of patients with LBP.

Effect of knee and hip position on hip extension range of motion in individuals with and without low back pain.

STUDY DESIGN: A 2-group, nonrandomized, mixed design with 1 between-subjects factor (group) and 2 within-subjects factors (knee and hip position). OBJECTIVES: To determine the amount of passive hip extension during changes in the knee angle in the sagittal plane, and the hip angle in the frontal plane in back-healthy (BH) subjects and subjects with low back pain (LBP). BACKGROUND: Information regarding the specific contributions of hip flexor muscles to limitations in hip extension range of motion (ROM) is necessary for the prescription of appropriate treatment. METHODS AND MEASURES: Thirty-five BH subjects (24 women and 11 men, mean age = 31.37 +/- 11.36) and 10 subjects with LBP (6 women and 4 men, mean age = 33.70 +/- 9.31) participated in the study. The passive length of the one- and two-joint hip flexor muscles was tested in 4 different conditions in which the positions of the knee and the hip were varied. The knee was positioned passively in full extension or 80 degrees of flexion while the hip was positioned passively in zero abduction or full abduction. RESULTS: Subjects with LBP displayed less passive hip extension than BH subjects (LBP, -5.61 degrees +/- 4.30; BH, -2.57 degrees +/- 4.18). Both groups had less hip extension when the knee was in flexion of 80 degrees than when the knee was fully extended (flexed, -5.51 +/- 4.50; extended, -0.98 degrees +/- 4.65), and when the hip was in zero hip abduction than when the hip was fully abducted (zero, -7.55 degrees +/- 5.03; full, 1.06 degrees +/- 4.31). The contribution of the different hip flexors to a hip extension limitation differed between BH and subjects with LBP. BH subjects demonstrated an effect of knee angle on hip extension when the hip was in zero abduction (flexed, -11.43 degrees +/- 5.81; extended, -2.49 degrees +/- 5.39), but not when the hip was in full abduction (flexed, 1.74 degrees +/- 3.91; extended, 1.89 degrees +/- 3.94). Subjects with LBP demonstrated an effect of knee angle on hip extension when the hip was in zero abduction (flexed, -12.60 degrees +/- 4.91; extended, -6.65 degrees +/- 5.03) and when the hip was in full abduction (flexed, -3.10 degrees +/- 5.53; extended, -0.10 degrees +/- 5.18). CONCLUSIONS: The results of this study provide evidence that changing the knee joint angle in the sagittal plane and the hip joint angle in the frontal plane, during the hip flexor length test, can affect the amount of passive hip extension ROM. The contribution of specific hip flexor muscles to a hip extension limitation may differ depending on the individual's movement dysfunction. Modifying the hip flexor length test, as described, should provide information about the specific muscles contributing to a hip joint extension limitation.

Reliability of physical examination items used for classification of patients with low back pain.

BACKGROUND AND PURPOSE: The purpose of this study was to examine the interrater reliability of measurements obtained by examiners administering tests proposed to be important for classifying low back pain (LBP) problems. SUBJECTS: Ninety-five subjects with LBP (41 men, 54 women) and 43 subjects without LBP (17 men, 26 women) were examined by 5 therapists trained in the techniques used. METHODS: A manual was developed by the first author that described the clinical examination procedures. The therapists were trained by the first author in the test procedures and definitions. The training included instruction through videotapes, practice and a written examination. Each examination was conducted by a pair of therapists. Within a pair, a therapist was the primary examiner for half of the subjects and an observer was the primary examiner for half of the subjects. Examination findings were recorded independently, without discussion. RESULTS: Percentage of agreement and generalized kappa coefficients were used to analyzed the data. Kappa values were > or = .75 for all 28 items related to the symptoms elicited and > or = .40 for 72% of the 25 items related to alignment and movement. CONCLUSION AND DISCUSSION: The results suggest that experienced therapist who had trained together were able to agree on the results of examinations and obtain an acceptable level of reliability. Future work should focus on testing of reliability when more than one therapist performs the examination and when therapist not trained by the test developer to administer the examination perform the tests. [Van Dillen LR, Sahrmann SA, Norton BJ, et al. Reliability of physical examination items used for classification of patients with low back pain.

Polarity effects on wound healing using electric stimulation in rabbits.

The aims of this study were to examine effects of high-voltage stimulation (HVS) on wound closure, tensile properties, and mitotic activity. Thirty-six rabbits were assigned to experimental (n = 18) or control groups. Each animal was anesthetized and a full-thickness incision, 3.5 cm long, was made on its back. After 24 hours, experimental rabbits received HVS for two hours, twice daily, for seven days. Polarity was negative the first three days and positive thereafter. Wound closure for HVS treated rabbits was 100%, which was significantly better than that of control rabbits (87%). Tensile strength values and mitotic activity for experimental and control rabbits were comparable. Histologic examination of the wounds suggested a more rapid rate of epithelialization in treated rabbits. Results suggest that electric stimulation, as given, augments wound closure.

Electrical stimulation effects on cutaneous wound healing in rabbits. A follow-up study.

The purpose of this study was to determine the effects of high voltage monophasic pulsed electrical stimulation on wound healing using positive polarity. Forty-four rabbits were assigned to experimental or control groups and followed for four or seven days. We classified the groups as Exp4, Con4, Exp7, and Con7, respectively. Each animal was anesthetized, and a full-thickness incision, 3.5-cm long, was made on its back. After 24 hours, the Exp4 and Exp7 rabbits received high voltage electrical stimulation for two hours twice daily. Wound closure for the Exp4 rabbits (50%) was significantly less than that of the Con4 rabbits (78%). After seven days, however, the Exp7 and Con7 rabbits had similar wound-closure values (80% and 82%, respectively). Tensile-strength values for the control and experimental animals were comparable at both time periods. Histologic examination of the wounds suggested a more rapid rate of epithelization between the Exp4 and Exp7 rabbits compared with the Con4 and Con7 rabbits. The results of this study are inconclusive, but may indicate that positive-polarity stimulation enhanced wound closure between four and seven days of treatment.

Electrically elicited fatigue test of the quadriceps femoris muscle. Description and reliability.

The purposes of this study were to develop an electrically elicited fatigue test (EEFT) that uses electrically elicited isometric muscle contractions and to examine the reliability of this test on a group of healthy individuals. Fifteen subjects were tested on two occasions, one week apart. The subjects were seated and the left leg secured to an isokinetic dynamometer with the knee positioned at 45 degrees of flexion. Maximum voluntary isometric contraction (MVIC) of the quadriceps femoris muscle was obtained and resultant knee extension torque was recorded. The quadriceps femoris muscle then was stimulated 50 times at the current level that elicited a knee extension torque level equal to 60% of that obtained during the MVIC. Percentages of decline in torque were calculated. Test-retest reliability indexes were calculated for the means of contractions 21 to 25 (r = .82, ICC = .83) and for contractions 46 to 50 (r = .92, ICC = .82). The EEFT was found to be reliable and may provide a clinically applicable means of measuring peripheral muscle fatigue.