Trunk extension effort in patients with chronic low back dysfunction

Effects of Virtual Reality Exercises versus Isokinetic Exercises in comparison with Conventional Exercises on the Imaging Findings and Inflammatory Biomarker Changes in Soccer Players with Non-Specific Low Back Pain: A Randomized Controlled Trial

Chronic non-specific low back pain (CNLBP) is the most common musculoskeletal problem. The purpose of this study was to investigate the effects of advanced physiotherapeutic exercise programs on imaging findings and inflammatory biomarkers in soccer players with CNLBP. In total, 60 CNLBP participants were divided into virtual reality exercise (VRE; n = 20), isokinetic exercise (IKE; n = 20), and conventional exercise (n = 20) groups. Pain intensity, imaging findings (muscle cross-sectional area (CSA) and muscle thickness), and changes in inflammatory biomarkers (CRP, TNF-α, IL-2, IL-4, and IL-6) were measured at baseline and after four weeks. After four weeks of intervention, there was a significant improvement (p = 0.001) in pain intensity for the VRE vs. IKE (0.7; CI 95% 0.38 to 1.07) and VRE vs. conventional (3.0 CI 95% 2.68 to 3.31) groups. The IKE group showed a greater number of significant changes in muscle CSA and muscle thickness than the other two groups (p < 0.001). Moreover, the VRE group showed significant improvement in inflammatory biomarker measures compared with the other two groups (p < 0.001). In CNLBP, virtual and isokinetic exercises had equal effects on reducing pain intensity. Isokinetic exercise is beneficial in increasing the muscle CSA and thickness, and virtual exercises are helpful for attenuating the inflammation process in soccer players with CNLBP.

Practicable performance-based outcome measures of trunk muscle strength and their measurement properties: A systematic review and narrative synthesis

Introduction

The evaluation of muscle strength is frequently used as part of the physical examination process, with decreased trunk muscle strength reported in individuals with spinal disorders (e.g., low back pain). Access to practicable performance-based outcome measures (PBOM) to monitor patients’ progress in spinal rehabilitation is essential. Knowledge of the psychometric properties of the available practicable PBOM for trunk strength evaluation is therefore needed to inform practitioners and further research.

Objective

To synthesise evidence on the measurement properties of practicable measures of trunk muscle strength in adults with and without musculoskeletal pain.

Methods

Following a published and registered protocol [PROSPERO CRD42020167464], databases were searched from the database inception date up to 30th of June 2021. Citations and grey literature were also searched. Eligibility criteria comprised: 1) studies which examined the psychometric properties of the trunk strength outcome measures, 2) included adults ≥ 18 years, either asymptomatic or with spinal musculoskeletal pain. Non-English language studies were excluded. Two independent reviewers evaluated the quality and synthesized the data from included studies according to the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist. The overall quality of evidence was evaluated using a modified Grading of Recommendations Assessment Development and Evaluation (GRADE).

Results

From 34 included studies, 15 different PBOMs were identified that have been investigated for reliability and validity, none evaluated responsiveness. In asymptomatic individuals, high quality evidence supports intra-rater reliability of digital-loading cells and moderate quality evidence supports the criterion validity of the hand-held dynamometer. Very low quality evidence exists for the reliability and validity estimates of testing tools among individuals with spinal pain.

Conclusions

Findings underpin a cautious recommendation for the use of practicable PROMs to evaluate muscle strength in individuals with spinal pain in clinical practice due to the level of evidence and the heterogeneity of the protocols used. Further high quality research to explore the psychometric properties of the practicable PBOMs with detailed methodology is now needed.

Wrist flexion and extension strength in patients with work-related chronic elbow pain: the isokinetic effort factor and its implications

BACKGROUND

The validity of isokinetic strength findings relating to forearm muscles in patients with chronic elbow pain and/or epicondylitis is not well established. Furthermore, given the nature of this disorder, ensuring maximal effort in performing the tests is an essential prerequisite. The isokinetic-based DEC parameter (defined as the difference between high- and low-velocity eccentric-to-concentric ratios of a given muscle) has been shown to efficiently detect maximal effort. The purpose of this study was therefore to assess the validity of isokinetic strength tests in patients with chronic elbow pain and/or epicondylitis.

METHODS

A cohort consisting of 44 male patients with chronic elbow pain (average evolution time, 262 ± 193.04 days) was recruited. The wrist extensor and flexor concentric and eccentric isokinetic strength of the involved and uninvolved sides was measured. The involved-uninvolved and flexor-extensor (F/E) ratios, as well as the DEC (eccentric-concentric difference), were computed based on peak moment values. Work disability and relapse within the first year were registered. In maximal performers, associations between deficits, F/E ratios, work disability, and symptom relapse were explored applying multiple comparisons.

RESULTS

Of the patients, 68.2% met the maximal-effort criteria, with the involved-side muscles being significantly weaker than their uninvolved-side counterparts in most cases. Although the mean deficit in this group was not associated with either work disability or relapse, patients with a relapse of symptoms within the first year had a significantly higher F/E ratio than those without relapse.

CONCLUSION

In patients presenting with chronic elbow pain who perform at the maximal level of effort, high wrist F/E strength ratios may predict symptom relapse.

Virtual reality or isokinetic training; its effect on pain, kinesiophobia and serum stress hormones in chronic low back pain: A randomized controlled trial

BACKGROUND

Evidence on the latest technologies in rehabilitation for reducing pain and altering serum stress hormones in low back pain (LBP) was lacking.

OBJECTIVE

To find the clinical and hormonal effects of virtual reality training (VRT) and isokinetic training (IKT) in chronic LBP patients.

METHODS

Through the simple random sampling method, 60 university football players with chronic LBP were allocated into three groups: NVRT= 20, NIKT= 20 and NCONTROL= 20. The three groups underwent different exercises for 4 weeks. Clinical (pain intensity and kinesiophobia) and hormonal (glucose, insulin, HOMA-IR, growth hormone, prolactin, ACTH and cortisol) values were measured at baseline, after 4 weeks and 6 months.

RESULTS

Four weeks following training, the VRT and IKT groups showed significant changes in pain intensity and kinesiophobia in comparison to the control group (p< 0.05). Hormonal measures also showed significant improvement in the VRT group in comparison to the other two groups (p< 0.05).

CONCLUSION

Training through virtual reality and isokinetic exercise is an effective approach in terms of pain and kinesiophobia. In terms of hormonal analysis, virtual reality shows slightly more improvements than isokinetic training in subjects with chronic LBP.

Isokinetic Trunk Strength in Acute Low Back Pain Patients Compared to Healthy Subjects: A Systematic Review

BACKGROUND

The purpose of this systematic review was to: (I) determine the quality of evidence from studies assessing trunk isokinetic strength in subjects with acute low back pain (ALBP) compared to healthy subjects and (II) establish reference values of isokinetic trunk strength in subjects with ALBP.

METHODOLOGY

Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statements were followed using keywords associated with trunk, strength and low back pain. Four databases were used: PubMed, Web of Science, Scopus and SPORTDiscus. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS).

RESULTS

A total of 1604 articles were retrieved, four included in this review. All were evaluated as high risk of bias (Rob). Due to the high Rob and the diversity of protocols, instruments and variables used, it was not possible to determine reference values for subjects with ALBP, we can only establish a range of flexion peak torque (PT) between 175.1 and 89.7 Nm at 60°/s and between 185 and 81.5 Nm at 120°/s, and for extension PT between 240.0 and 91.5 Nm at 60°/s and between 217.5 and 69.2 Nm at 120°/s in subjects with ALBP.

CONCLUSIONS

Due to the low quality of the evidence and the diversity of protocols used when measuring trunk isokinetic strength, it is necessary to carry out new high-quality research to establish reference values of trunk strength in subjects with ALBP.

Detection of effort maximality in adults performing isokinetic wrist flexion and extension

BACKGROUND: The difference between isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) is a powerful tool for identifying submaximal effort in other muscle groups but its efficiency in terms of the wrist extensors (WE) and flexors (WF) isokinetic effort has hitherto not been studied. OBJECTIVE: The objective of the present study is to examine the usefulness of the DEC for identifying suboptimal wrist extensor and flexor isokinetic efforts. METHODS: Twenty healthy male volunteers aged 20–40 years (28.5 ± 3.2) were recruited. Participants were instructed to exert maximal and feigned efforts, using a range of motion of 20∘ in concentric (C) and eccentric (E) WE and WF modes at two velocities: 10 and 40∘/s. E/C ratios (E/CR) where then calculated and finally DEC by subtracting low velocity E/CR from high velocity ones. RESULTS: Feigned maximal effort DEC values were significantly higher than their maximal effort counterparts, both for WF and WE. For both actions, a DEC cutoff level to detect submaximal effort could be defined. The sensitivity of the DEC was 71.43% and 62.5% for WE ad WF respectively. The specificity was 100% in both cases. CONCLUSION: The DEC may be a valuable parameter for detecting feigned maximal WF and WE isokinetic effort in healthy adults.

Isokinetic training - its radiographic and inflammatory effects on chronic low back pain: A randomized controlled trial

BACKGROUND

Isokinetic training (IKT) and core stabilization training (CST) are commonly used for balance training in musculoskeletal conditions. The knowledge about the effective implementation of these training protocols on radiological and biochemical effects in university football players with chronic low back pain (LBP) is lacking.

OBJECTIVE

To find and compare the effects of isokinetic training and CST on radiological and biochemical effects in university football players with chronic LBP.

DESIGN

Randomized, double-blinded controlled study.

SETTING

University hospital.

PARTICIPANTS

60 LBP participants were randomized into isokinetic group (IKT; n = 20), core stabilization group (CST; n = 20) and the control group (n = 20) and received respective exercises for 4 weeks.

OUTCOME MEASURES

Radiological (muscle cross sectional area & muscle thickness) and biochemical (C-reactive protein, tumor necrosis factor -α, interleukin [IL]-2, IL-4, IL-6) values were measured at baseline and after 4 weeks (immediate effect).

RESULTS

The reports of the IKT, CST and control group were compared between the groups. Four weeks following training IKT group shows more significant changes in muscle cross sectional area (Psoas Major, Quadratus Lumborum, Multifidus and Erector Spinae muscles) and muscle thickness (Multifidus) than CST and control groups (p < 0.001). Biochemical measures such as C-reactive protein, tumor necrosis factor -α, IL-2, IL-4 and IL-6 also show significant improvement in IKT group than the other 2 groups (P < .001).

CONCLUSION

Training through Isokinetic is an effective treatment program than conventional exercise programs in the aspect of radiological and biochemical analysis in university football players with chronic LBP, which may also help to prevent further injury. The present study can be used to improve the physical therapist's knowledge and clinical decision skills on LBP in football players.

Comparative Effects of Isokinetic Training and Virtual Reality Training on Sports Performances in University Football Players with Chronic Low Back Pain-Randomized Controlled Study

Objective

The objective of this study is to find and compare the effects of isokinetic training and virtual reality training on sports performances in university football players with chronic low back pain.

Design

This is a randomized, double-blinded controlled study.

Methods

The study was conducted on 45LBP participants at university hospital. First group (n = 15) received isokinetic training, second group (n = 15) received virtual reality training, and the control group (n = 15) received conventional training exercises for four weeks. Clinical (pain intensity and player wellness) and sports performance (40 m sprint, 4 × 5 m sprint, submaximal shuttle running, countermovement jump, and squat jump) scores were measured at baseline, after 4 weeks, 8 weeks, and 6 months.

Results

Four weeks following training VRT group shows more significant changes in pain intensity and player wellness scores than IKT and control groups (p ≤ 0.001). Sports performance variables (such as 40 m sprint, 4 × 5 m sprint, submaximal shuttle running, countermovement jump, and squat jump) scores also show significant improvement in VRT group than the other two groups (p ≤ 0.001).

Conclusion

Overall, our study suggests that strength training through virtual reality training protocol improves pain and sports performances than isokinetic training and other conventional trainings in university football players with chronic low back pain.

Isokinetic back training is more effective than core stabilization training on pain intensity and sports performances in football players with chronic low back pain: A randomized controlled trial

BACKGROUND

Isokinetic training (IKT) and core stabilization training (CST) are commonly used for balance training in musculoskeletal conditions. The knowledge about the effective implementation of these training protocols on sports performances in university football players with chronic low back pain (LBP) is lacking.

OBJECTIVE

To find and compare the effects of IKT and CST on sports performances in university football players with chronic LBP.

DESIGN

Randomized, double-blinded controlled study.

SETTING

University hospital.

PARTICIPANTS

Sixty LBP participants divided into isokinetic group (IKT; n = 20), core stabilization group (CST; n = 20), and the control group (n = 20) and received respected exercises for 4 weeks.

OUTCOME MEASURES

Clinical (pain intensity and player wellness) and sports performances (40 m sprint, 4 × 5 m sprint, submaximal shuttle running, counter movement jump, and squat jump) scores were measured at baseline, after 4 weeks, 8 weeks, and 3 months.

RESULTS

Four weeks following training IKT group shows more significant changes in pain intensity and player wellness scores than CST and control groups (P ≤ .001). Sports performance variables (40 m sprint, 4 × 5 m sprint, submaximal shuttle running, counter movement jump and squat jump) scores also show significant improvement in IKT group than the other 2 groups (P ≤ .001).

CONCLUSION

This study suggests that training through IKT improves pain intensity and sports performances than CST in university football players with chronic LBP.

Effects of Kinesio tape application to trunk isokinetic strength in female participants

The purpose of this study is to analyse the effects of KT on trunk strength with respect to different angular speeds when applied to the trunks of healthy women. Forty healthy female participants were randomly distributed into two groups: the placebo group (PG) in which placebo KT was applied and the experimental group (EG). Participants' trunk concentric flexion and extension muscle strength were measured using an isokinetic dynamometer in two different angular speeds (60°/s - 180°/s). In both PG and EG groups, there was no significant difference measured immediately after taping at the two angular speed values. In the measurements taken 48 h later, as regards PG trunk flexion, extension muscle strength increased significantly (p = 0.0001) at 60°/sc. angular speed while, for the EG only, the strength of trunk extension muscle increased significantly (p = 0.002). It was observed, that to ensure an increase in strength, waiting for a certain length of time was required. Lower angular speeds and short-term applied KT improved the strength of the trunk extension muscle.

Age-related reduction of trunk muscle torque and prevalence of trunk sarcopenia in community-dwelling elderly: Validity of a portable trunk muscle torque measurement instrument and its application to a large sample cohort study

Trunk muscle weakness and imbalance are risk factors for postural instability, low back pain, and poor postoperative outcomes. The association between trunk muscle strength and aging is poorly understood, and establishing normal reference values is difficult. We aimed to establish the validity of a novel portable trunk muscle torque measurement instrument (PTMI). We then estimated reference data for healthy young adults and elucidated age-related weakness in trunk muscle strength. Twenty-four university students were enrolled to validate values for PTMI, and 816 volunteers from the general population who were recruited to the Iwaki Health Promotion Project were included to estimate reference data for trunk muscle strength. Trunk flexion and extension torque were measured with PTMI and KinCom, and interclass correlation coefficients (ICC) were estimated to evaluate the reliability of PTMI values. Furthermore, from the young adult reference, the age-related reduction in trunk muscle torque and the prevalence of sarcopenia among age-sex groups were estimated. The ICC in flexion and extension torque were 0.807 (p<0.001) and 0.789 (p<0.001), respectively. The prevalence of sarcopenia increased with age, and the prevalence due to flexion torque was double that of extension torque. Flexion torque decreased significantly after 60 years of age, and extension torque decreased after 70 years of age. In males over age 80, trunk muscle torque decreased to 49.1% in flexion and 63.5% in extension. In females over age 80, trunk muscle torque decreased to 60.7% in flexion and 68.4% in extension. The validity of PTMI was confirmed by correlation with KinCom. PTMI produced reference data for healthy young adults, and demonstrated age-related reduction in trunk muscle torque. Trunk sarcopenia progressed with aging, and the loss of flexion torque began earlier than extension torque. At age 80, trunk muscle torque had decreased 60% compared with healthy young adults.

Standard and Short RoM Isokinetic Testing: Comparative Analysis in Identifying Submaximal Shoulder External Rotator Effort

An isokinetic-related parameter termed the difference between eccentric-concentric strength ratios at two distinct test velocities (DEC) based on 60° (standard) range of motion (RoM) has been proven to be highly efficient detecting feigned muscular efforts. This study aimed to verify whether a DEC derived from a much shorter test RoM (20°) was equally useful than a long RoM-derived one. Eighteen healthy men (32.4 ± 6.4 years old) took part in a study focusing on shoulder external rotation isokinetic strength. Participants performed a genuine shoulder external rotator maximal effort (eight pairs of concentric and eccentric contractions at high and low velocities at short and long RoM) and then instructed to feign maximal effort. Contraction velocities were adjusted accordingly by applying a 1:4 gradient and peak moments registered. Both condition DEC was then calculated by subtracting the eccentric and concentric strength ratios at low velocities from those at high velocities. DEC scores in the feigned effort were significantly higher than maximal effort ones in both conditions in men. It enabled the setting of specific cutoff levels for separating the efforts. Both approaches revealed a coincident sensitivity (78%) whereas short RoM showed an even higher specificity: 88% versus 78%. Thus, the short RoM protocol provides clinically acceptable detection power.

A kinematic analysis for shoulder and pelvis coordination during axial trunk rotation in subjects with and without recurrent low back pain

The purpose of this study was to compare the kinematics of the shoulder and pelvis based on range of motion (ROM), angular velocity, and relative phase (RP) values during trunk axial rotation. Nineteen subjects with recurrent low back pain (LBP) and 19 age-matched control subjects who are all right limb dominant participated in this study. All participants were asked to perform axial trunk rotation activities at a self-selected speed to the end of maximum range in a standing position. The outcome measures included ROM, angular velocity, and RP on the shoulder and pelvis in the transverse plane and were analyzed based on the demographic characteristics between groups. The LBP group demonstrated decreased ROM (p=0.02) and angular velocity (p=0.02) for the pelvis; however, there was no group difference for the shoulder girdle. The ROM difference between the shoulder and pelvic transverse planes had a significant interaction with age (F=14.75, p=0.001). The LBP group demonstrated a higher negative correlation between the shoulder (r=-0.74, p=0.001) and pelvis (r=-0.72, p=0.001) as age increased while no significant correlations were found in the control group. The results of this study indicated that there was a difference in pelvic rotation in the transverse plane between groups during axial trunk rotation. It would be important to coordinate postural stability between the shoulder and pelvic girdles during ambulation; however, the pattern of trunk movement decreased with age due to possible pelvic stiffness in subjects with recurrent LBP. Therefore, improved pelvic flexibility for coordinated trunk movement patterns would help subjects with recurrent LBP.

The effect of horse simulator riding on visual analogue scale, body composition and trunk strength in the patients with chronic low back pain

BACKGROUND

Chronic low back pain (CLBP) is one of the most common musculoskeletal disorders, and thus effective treatments are required. Recently, real horseback riding has been reported to be beneficial for the patients. However, it has some limitations, such as limited approaches and safety issues.

OBJECTIVE

The purpose of this study was to investigate the effect of horse simulator riding on back pain, body composition and trunk strength in the patients with CLBP.

PARTICIPANTS

Forty-seven men with CLBP (mean age 20.55 ± 1.38 years) were randomly divided into a control group (n = 23) and a horse simulator riding group (n = 24), and visual analogue scale (VAS), body composition and isokinetic trunk strength were measured after 8 weeks for which subjects in a horse simulator riding group had performed the horse simulator exercise (HSE).

RESULTS

Horse simulator exercise significantly reduced pain scores of VAS and enhanced isokinetic torques of trunk at 30 and 90°/s. There were also significantly increased muscle mass and decreased fat mass in horse simulator riding group.

CONCLUSION

It can be inferred that HSE may be helpful in relief of back pain and recovery of back function through developing trunk strength and balancing the ratio of trunk flexor/extensor muscles.

Discriminating between maximal and feigned isokinetic knee musculature performance using waveform similarity measures

BACKGROUND

Muscle strength test outcomes may aid in determination of impairment or disability rating following injury. In such settings, verification of participant effort during testing is imperative. This investigation explored the utilization of within-set moment waveform similarity measures, namely cross correlation and percent root mean square difference scores, to develop decision rules for discriminating between maximal and feigned efforts during isokinetic testing of the knee joint musculature.

METHODS

A mixed-gender sample of 46 participants performed non-reciprocal sets of maximal or feigned knee extension and flexion concentric and eccentric efforts at testing velocities of 30°s(-1) and 120°s(-1). Logistic regression and Monte Carlo simulations were used to derive decision rules for differentiating between the two effort types.

FINDINGS

Employing cutoff scores corresponding to 100% specificity; sensitivities of the knee extensor's velocity-specific decision rules were 92.4% and 84.8%, respectively. The velocity-specific knee flexor's test sensitivities were 56.5% and 46.7%.

INTERPRETATION

Utilizing the proposed decision rules, substantiating maximal effort performance of the knee extensors may be possible using this specific testing protocol. However, the proposed methods are limited in their ability to verify performance of maximal knee flexor efforts.

A comparison of pain level and entropy changes following core stability exercise intervention

Background

As reported in our previous studies, the complexity of physiologic time series is a sensitive measure of muscle fatigability. This study compared the differences between 2 different analyses following 4 weeks of core stability exercises (CSE) in subjects with and without chronic low back pain (LBP). We examined whether the observed Shannon (information) entropy, as compared with median frequency (MF), was able to differentiate fatigability of the thoracic and lumbar parts of the erector spinae (ES) muscles following the intervention.

Material/Methods

In total, 32 subjects participated in this study. There were 13 subjects in the CSE intervention group (average age 50.4±9.1 years) and 19 subjects in the control group (average age 46.6±9.1 years). The CSE group performed the specific exercise intervention, but the control group was asked to maintain their current activity and/or exercise levels. The endurance of the back muscles was determined by using a modified version of the isometric fatigue test as originally introduced by Sorensen.

Results

Pain level decreased significantly for all subjects (F=25.29, p=0.001), but there was no difference between groups (F=0.42, p=0.52). The MF was not different between groups following treatment (F=0.81, p=0.37). Although there was no entropy level changes following treatment (F=0.01, p=0.93), the interactions between muscles and groups following treatment were significant (F=7.25, p=0.01). The entropy level decreased in both thoracic ES muscles following intervention in the exercise group, while remaining the same in the control group.

Conclusions

Although the change in pain level was not different between groups, the Shannon entropy measure more sensitively differentiated the exercise intervention than did MF. In addition, the results also suggested that complexity is related to muscle fatigue, which corresponds to the values of entropy between groups. Further studies are needed to investigate the effectiveness of nonlinear time series of EMG data for fatigability.

The eccentric, concentric strength relationship of the hamstring muscles in chronic low back pain

OBJECTIVE

The objective of this study was to measure hamstring muscle eccentric and concentric strength in individuals with and without low back pain (LBP). Two composite scores for the relative balance of eccentric to concentric strength at the different movement velocities were calculated (the DEC and SEC), to determine whether or not self perceived pain, disability, or fear avoidance measures were associated with hamstring strength characteristics.

DESIGN

Cross-sectional repeated measures design.

SETTING

University laboratory.

PARTICIPANTS

Fifteen individuals with chronic LBP and 15 matched controls.

MAIN OUTCOME MEASURES

Isokinetic eccentric and concentric strength at 30 degrees s(-1) and 120 degrees s(-1)(.) Composite scores (DEC and SEC) based on peak torque were calculated to evaluate the relationship between the different muscle actions across the test velocities. Self report measures included the Oswestry disability index, general health and well being, fear avoidance, and pain.

RESULTS

Eccentric/concentric strength ratio at 30 degrees s(-1) was higher for the LBP group (F(1,58)=4.81, p=0.032). The SEC was also higher for the LBP (F(1,58)=5.97, p=0.018). Fear avoidance beliefs and mental well-being were significantly associated with the SEC only in the LBP group (adjusted r(2)=0.26, (F(2,27)=5.8, p=.008). For the control group both the DEC and SEC were associated with self report measures. Matched differences between groups' for the SEC were best explained by fear avoidance beliefs about work (adjusted r(2)=0.12, F(1,28)=5.1, p=0.03).

CONCLUSION

Reduced concentric relative to eccentric strength is best identified by the SEC. The SEC was significantly associated with impaired self report measures of fear avoidance and mental well being in individuals with LBP. Differences between groups for the SEC were best explained by fear avoidance beliefs about work.

Comparison of isokinetic exercise versus standard exercise training in patients with chronic low back pain: a randomized controlled study

OBJECTIVE

To compare the effectiveness of an isokinetic exercise programme and a standard exercise programme in patients with chronic low back pain in terms of pain, mobility, disability, psychological status and muscle strength.

DESIGN

A randomized controlled trial.

SETTING

An outpatient rehabilitation clinic.

SUBJECTS

A total of 40 patients with low back pain were included in the study.

INTERVENTIONS

Patients with low back pain were randomly allocated into group 1 (n=20, isokinetic exercises) and group 2 (n=20, standard exercise).

MAIN MEASURES

Outcome measures included a visual analogue scale (VAS) for pain, fingertip-to-floor test for spinal mobility, Modified Oswestry Low Back Disability Questionnaire (MOLBDQ), Beck Depression Inventory and isokinetic muscle testing.

RESULTS

The isokinetic and standard exercise groups demonstrated significant improvement in the VAS, fingertip-to-floor test, MOLBDQ, Beck Depression Inventory scores, and muscle strength compared with the baseline that persisted until the end of the first month (P<0.05). Comparison of both exercise groups in terms of these parameters obtained at the end of the treatment and at the first month after treatment showed no significant difference (P>0.05).

CONCLUSION

Isokinetic and standard exercise programmes have an equal effect in the treatment of low back pain, with no statistically significant difference found between the two programmes. The standard exercise programme was easily performed and had a low cost, making it the preferred option for exercise.

Quadriceps and hamstring isokinetic strength and electromyographic activity measured at different ranges of motion: a reproducibility study

Isokinetic strength measurements of the quadriceps and hamstring that are commonly conducted using a 90 degrees range of motion (RoM) may involve some risk to specific knee patient groups. Testing these muscles at a much shorter RoM may reduce the risk but in order to render this method clinically acceptable the reproducibility of the derived test findings has to be established. Therefore the main objective of this study was to assess the reproducibility of isokinetic peak torque and normalized EMG scores of these muscles based on 90 degrees (0-90 degrees flexion, LR) and three successive short RoMs: 0-30 degrees (SR1), 30-60 degrees (SR2) and 60-90 degrees (SR3). Eight healthy subjects were tested three times with a 2 week between-session interval. All tests were performed on the dominant limb and consisted of maximal concentric and eccentric exertions. The velocities applied were 90 degrees /s for LR and 30 degrees /s for each of the SRs. Findings indicated no between-session improvement in strength. Based on the coefficient of variation the measurement error for all isokinetic strength scores remained stable throughout the testing sessions ranging 0.6-13.9% with the absolute majority of instances less than 10%. The reproducibility of the EMG scores was poorer ranging 1.5-25% and 0.5-19% for the quadriceps and hamstring, respectively. It is concluded that testing of knee muscles at short (30 degrees ) RoMs does not compromise the reproducibility of the strength or EMG scores derived from the commonly used RoM of 90 degrees . However, whereas strength was reproducible to within the accepted clinical standards, the corresponding EMG scores were characterized by a wider error band.

Endurance Times of Trunk Muscles in Male Intercollegiate Rowers in Hong Kong

OBJECTIVES

To establish isometric endurance times of trunk muscles and their ratios in a group of healthy intercollegiate rowers in Hong Kong for clinical assessment reference, and to compare the trunk endurance profile of the rowers in the current study with that of nonrowers in another study.

DESIGN

Isometric endurance times were measured in 4 different positions in a cross-sectional manner. A subset of 5 subjects was tested 3 times 2 days and 1 week apart to evaluate reliability.

SETTING

Sports medicine department of a national sports institute.

PARTICIPANTS

Thirty-two subjects selected from a group of 42 male intercollegiate rowers reported to have more than 6 months of rowing experience and without history of low back pain.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Trunk muscle endurance times in seconds and ratios of endurance times normalized to that of the extensor muscle.

RESULTS

The trunk flexor (mean +/- standard deviation, 176.56+/-88.58 s) had the best endurance times among all the trunk muscles tested (extensor mean, 114.28+/-34.62 s; left lateral flexor mean, 94.53+/-32.97 s; right lateral flexor mean, 98.13+/-41.38 s). No significant difference was found between the left and right lateral flexors (P<.05). The lateral flexor and the flexor endurance times were 85% and 154% of that of the extensor, respectively. The testing protocol in this group of rowers showed good to excellent reliability (intraclass correlation coefficient range, .76-.93).

CONCLUSIONS

Intercollegiate rowers in Hong Kong have better endurance in their trunk flexor than the extensor; the lateral flexors are of similar endurance capacity. These findings are different from the endurance profile reported for nonrowers in a previous study. Such differences should be considered when evaluating trunk endurance times in rowers for rehabilitation and training.

On the diagnosis of malingered pain-related disability: lessons from cognitive malingering research

BACKGROUND CONTEXT

Pain-related disability is a complex phenomenon. Malingering is a potential factor in the management of patients with pain. Methodological problems and inappropriate expectations regarding diagnostic accuracy have hampered the study of malingering detection in pain. In contrast, the study of cognitive malingering in neuropsychology has led to the development of many highly accurate and reliable detection techniques. This paper applies the methods and logic that have been successful for identifying cognitive malingering to the problem of malingering in patients with pain.

PURPOSE

Outline the logic of a research methodology for studying malingering detection in pain and introduce a system for the diagnosis of malingering in pain.

STUDY DESIGN

Literature review and conceptual synthesis.

METHODS

Examination of the research methodology and diagnostic scheme used in the study of cognitive malingering; adaptation of these methods to the problem of malingering in pain.

RESULTS

Lessons derived from the study of cognitive malingering were used to generate recommendations to enhance research into detection and diagnosis of malingered pain-related disability. A comprehensive, multidimensional system for diagnosing malingering in pain-related disability was proposed.

CONCLUSIONS

Pain-related disability is a multifaceted phenomenon, therefore malingering can occur in different and sometimes multiple dimensions. It is presently possible to accurately detect and diagnose malingering in some patients with pain. More work is needed for some detection techniques to be appropriately calibrated in pain populations. This work must focus on controlling the false positive error rate.