STUDY DESIGN: Quasi-experimental clinical trial. OBJECTIVES: This study compared outcomes from graded exercise and graded exposure activity prescriptions for patients participating in a multidisciplinary rehabilitation program for chronic low back pain. Our primary purpose was to investigate whether pain and disability outcomes differed based on treatment received (graded exercise or graded exposure). Our secondary purpose was to investigate if changes in selected psychological factors were associated with pain and disability outcomes. BACKGROUND: Behavioral interventions have been advocated for decreasing pain and disability from low back pain, yet relatively few comparative studies have been reported in the literature. METHODS: Consecutive sample with chronic low back pain recruited over a 16-month period from an outpatient chronic pain clinic. Patients received physical therapy supplemented with either graded exercise (n = 15) or graded exposure (n = 18) principles. Graded exercise included general therapeutic activities and was progressed with a quota-based system. Graded exposure included specific activities that were feared due to back pain and was progressed with a hierarchical exposure paradigm. Psychological measures were pain-related fear (Fear-Avoidance Beliefs Questionnaire, Tampa Scale for Kinesiophobia, Fear of Pain Questionnaire), pain catastrophizing (Coping Strategies Questionnaire), and depressive symptoms (Beck Depression Inventory). Primary outcome measures were pain intensity (visual analog scale) and self-report of disability (modified Oswestry Disability Questionnaire). RESULTS: Statistically significant improvements (P<.01) were observed for pain intensity and disability at discharge. The rate of improvement did not differ based on behavioral intervention received (P>.05 for these comparisons). Overall, 50% of patients met criterion for minimally important change for pain intensity, while 30% met this criterion for disability. Change in depressive symptoms was associated with change in pain intensity, while change in pain catastrophizing was associated with change in disability. CONCLUSIONS: Physical therapy supplemented with graded exercise or graded exposure resulted in equivalent clinical outcomes for pain intensity and disability. The overall treatment effects were modest in this setting. Instead of being associated with a specific behavioral intervention, reductions in pain and disability were associated with reductions in depressive symptoms and pain catastrophizing, respectively. LEVEL OF EVIDENCE: Therapy, level 2b–.

J Orthop Sports Phys Ther 2010;40(11):694-704, Epub 22 October 2010. doi:10.2519/ jospt.2010.3396

KEY WORDS: behavioral intervention, fear-avoidance model, pain catastrophizing

Traditionally, placebo has been associated with using an inert substance, in part so the subsequent response could
be attributed to the target treatment, controlling for the confound of a “placebo effect.” Placebo’s link with inert substances is so strong that “sham treatment” is a common synonym, and widespread placebo use is discouraged—even when there is supporting evidence for its effectiveness. Recent research has helped to redefine placebo, and this editorial will highlight key information supporting a contemporary view of placebo.

J Orthop Sports Phys Ther 2010;40(8):452-454. doi:10.2519/jospt.2010.0107

KEY WORDS: placebo effect, study design

STUDY DESIGN: Randomized, controlled trial. OBJECTIVES: To assess the believability of a novel sham intervention for a neurodynamic technique (NDT) in participants with signs and symptoms of carpal tunnel syndrome (CTS). Additionally, we wished to assess a potential mechanism of NDT (hypoalgesia) and to compare outcomes related to clinical pain and upper extremity disability between NDT and a sham intervention. BACKGROUND: Preliminary evidence suggests that NDT is effective in the treatment of CTS. A sham-controlled study is lacking from the literature and could provide insight to the efficacy of NDT, as well as the corresponding mechanisms. METHODS: Participants with signs and symptoms consistent with CTS provided baseline measures of expectation, clinical pain intensity, upper extremity disability, and experimental pain sensitivity. Participants were then randomly assigned to receive either a NDT known to anatomicallystress the median nerve or a sham technique intended to minimize stress to the median nerve. Following brief exposure to the assigned technique, expectation was reassessed to observe for group-dependent changes. Participants received the assigned intervention over 3 weeks. Additionally, all participants received a prefabricated wrist splint for their involved hands, with instructions to sleep in the splint and to wear it during painful activities when awake. Following 3 weeks of the assigned intervention and splint wear, baseline measures were reassessed and participants were asked which intervention they believed they had received. RESULTS: Forty females agreed to participate. Expectations for pain relief and perceived group assignment were similar between the groups. Within-session decreases in clinical pain intensity and pressure pain sensitivity were observed independent of group assignment. Reduction of temporal summation was observed only in participants receiving NDT. Significant improvements in clinical pain intensity and upper extremity disability were observed at 3 weeks, independent of group assignment. CONCLUSION: The sham intervention was successful in blinding the participants. Immediate changes in pain sensitivity and intensity and 3-week changes in clinical pain intensity and upper extremity disability associated with NDT were equivalent to a sham intervention to which the participants were adequately blinded. Conversely, reduction of temporal summation was only observed in participants receiving the NDT, suggesting the potential of a favorable neurophysiological effect. LEVEL OF EVIDENCE: Therapy, level 1b.

J Orthop Sports Phys Ther 2009;39(10):709-723. doi:10.2519/jospt.2009.3117

KEY WORDS: central sensitization, manual therapy, musculoskeletal pain, placebo

Letters to the Editor-in-Chief of the JOSPT as follows:

• Letter regarding the editorial, Risk and Physical Therapy?. J Orthop Sports Phys Ther. 2007:37(9):570-572. doi:10.2519/jospt.2007.0209.
• Authors' Response. J Orthop Sports Phys Ther. 2007:37(9):571-572. doi:10.2519/jospt.2007.0210.

STUDY DESIGN: Cross-sectional. OBJECTIVES: To (1) determine the association between pain severity and pain drawing area for men and women; (2) determine if sex differences exist in pain severity or pain drawing area; (3) determine the relative influence of pain sever­ity, anatomical location of pain, personality, and psychological coping factors on pain drawing area for men and women. BACKGROUND: Pain drawings have been pos­tulated to assist in clinical decision making regard­ing classification and treatment of musculoskeletal pain. Prior studies have been ambiguous on this topic, possibly because they have not considered if sex differences exist for pain drawing area. METHODS AND MEASURES: One hundred twenty-six subjects referred to a multidisciplinary chronic pain clinic with chronic musculoskeletal pain were included in this study. Subjects com­pleted a pain drawing, the Multidimensional Pain Inventory (MPI), the Coping Strategies Question­naire (CSQ), and the Minnesota Multiphasic Per­sonality Inventory (MMPI-2). Pearson correlations investigated the associations of pain severity and pain drawing area, independent t tests investigated sex differences in pain severity and pain drawing area, and multiple regression investigated factors that influenced pain drawing area. RESULTS: Pain severity was positively corre­lated with pain drawing area for men (r = 0.38, P = .003) and women (r = 0.23, P = .052), account­ing for approximately 14% and 5% of the total variance, respectively. There was no significant sex difference in pain severity ratings, but women reported a significantly larger area of symptoms on the pain drawings (effect size, 0.61; P = .002). The sex difference in pain drawing area was consistent across different anatomical locations of pain. In women, the final regression model accounted for 39% (P<.001) of the variance in pain drawing area, with anatomical location of pain (β = .42, P<.001) and hypochondriasis (β = .31, P = .005) as the only unique predictors in the final model. In men, the regression model accounted for 27% (P = .003) of the variance in pain drawing area, with pain severity (β = .32, P = .021) and a coping style of ignoring pain (β = –.32, P = .018) as the only unique predictors in the final model. CONCLUSIONS: Women had larger pain draw­ing area and this area was significantly associated with anatomical location of pain and hypochon­driasis. Men had smaller pain drawing area and this area was associated with pain severity and a coping style of ignoring pain. These findings sug­gest that clinicians interpreting pain diagram area should consider the sex of the individual. 

J Orthop Sports Phys Ther. 2007;37(3):115-121. doi:1.2519/jospt.2007.2399 

KEY WORDS: chronic pain, coping styles, personality style, pain drawing, sex difference, yellow flags

Study Design: Single group repeated measures design. Objective: To determine if the rate of transition between knee flexion and extension influences the subsequent concentric activation of the quadriceps and knee extension torque during reciprocal movements. Background: Preloading a muscle by stretching, a prior isometric or eccentric muscle action, or a prior movement controlled concentrically by the antagonist muscle group increases the maximal torque-generating capability of the agonist. We hypothesized that the rate of transition from the prior movement may be the critical factor that influences the degree of muscle facilitation and torque potentiation. Rapid reversal of antagonistic movements has been postulated as a potential facilitatory mechanism. Methods: Knee extension torque and electromyographic (EMG) amplitude (dependent variables) from 2 of the vasti muscles were recorded while subjects (N = 20; 12 men, 8 women, mean age, 28.5 ± 2.68 years) maximally activated their quadriceps at 3 constant angular velocities, 100°/s, 200°/s, and 300°/s, and 2 preload conditions, SLOW and RAPID (independent variables). In the SLOW transition condition, subjects actively flexed their knee to 110° from an extended position, paused in this position for 3 seconds, and then extended to O°. In the RAPID transition condition, the same movement from knee flexion to extension was performed without a pause. Results: Peak torque, the root-mean-square (RMS) average, peak (peak rectified and smoothed), and initial (100 milliseconds prior to torque onset) EMG amplitudes were all significantly greater during the RAPID transition condition. Peak torque decreased with increasing movement velocity. There were no interactions between the preload conditions and angular velocity on peak torque or the EMG amplitude variables. There was also no influence of velocity on the EMG amplitude variables. Conclusions: The effect of preloading the quadriceps by prior concentric activation of the hamstrings is dependent on the rate of transition between the flexion and extension movements and is due primarily to neural facilitation.

J Orthop Sports Phys Ther. 2001;31(4):122-132.

Key Words: exercise, muscle training. proprioceptive neuromuscular facilitation, quadriceps

The use of torque variability and slope measures to detect submaximal efforts has been studied in isometric tests, but not fully investigated in isokinetic tests. The purpose of this study was to investigate differences between maximal and submaximal efforts in isometric and isokinetic knee extension using torque variability and slope measures obtained from 32 volunteers (age = 25.2 ± 4.7 years). The coefficient of variation of average torque, coefficient of variation of peak torque, and slope to peak torque were obtained from maximal and submaximal torque curves during isometric and 2 isokinetic tests (60°/sec and 180°/sec). Significant differences between effort levels (maximal and submaximal were shown for all variables in isometric and isokinetic tests. An optimized cut-off value to determine submaximal efforts without false positives was determined for each variable. The coefficient of variation of average torque detected 75% of submaximal efforts at 180°/sec and slope to peak torque detected 63% of submaximal efforts at 60°/sec. For both speeds, combining the coefficient of variation of average torque with slope improved the submaximal detection rate to 84%. No variable provided a satisfactory detection rate for the isometric test. Therefore, submaximal isokinetic knee extensions are detectable with torque variability and slope measures, but submaximal isometric exercise is not detectable.

J Orthop Sports Phys Ther. 1996;24(1):19-24.

Key Words: muscle strength, knee, effort rating