A comprehensive guide to MEGA-PRESS for GABA measurement.

The aim of this guideline is to provide a series of evidence-based recommendations that allow those new to using MEGA-PRESS to produce high-quality data for the measurement of GABA levels using edited magnetic resonance spectroscopy with the MEGA-PRESS sequence at 3T. GABA is the main inhibitory neurotransmitter of the central nervous system and has been increasingly studied due to its relevance in many clinical disorders of the central nervous system. MEGA-PRESS is the most widely used method for quantification of GABA at 3T, but is technically challenging and operates at a low signal-to-noise ratio. Therefore, the acquisition of high-quality MRS data relies on avoiding numerous pitfalls and observing important caveats. The guideline was developed by a working party that consisted of experts in MRS and experts in guideline development and implementation, together with key stakeholders. Strictly following a translational framework, we first identified evidence using a systematically conducted scoping literature review, then synthesized and graded the quality of evidence that formed recommendations. These recommendations were then sent to a panel of 21 world leaders in MRS for feedback and approval using a modified-Delphi process across two rounds. The final guideline consists of 23 recommendations across six domains essential for GABA MRS acquisition (Parameters, Practicalities, Data acquisition, Confounders, Quality/reporting, Post-processing). Overall, 78% of recommendations were formed from high-quality evidence, and 91% received agreement from over 80% of the expert panel. These 23 expert-reviewed recommendations and accompanying extended documentation form a readily useable guideline to allow those new to using MEGA-PRESS to design appropriate MEGA-PRESS study protocols and generate high-quality data.

Is this back pain killing me? All-cause and cardiovascular-specific mortality in older Danish twins with spinal pain.

BACKGROUND: Few studies have examined the potentially reduced life expectancy associated with spinal pain (i.e. low back and neck pain) in an ageing population, particularly after controlling for familial factors, including genetics. METHODS: We investigated whether spinal pain increased the rate of all-cause and disease-specific cardiovascular mortality in older Danish twins aged ≥70 years. Data from 4391 participants collected at baseline were linked with the Danish Cause of Death Registry with the study ending on 31 December 2014. Two crude and adjusted Cox proportional hazards regression analyses determined the rate of all-cause and disease-specific cardiovascular mortality by baseline spinal pain exposure; unpaired (total sample analysis) and twin pair (intra-pair analysis). Analyses were also adjusted for confounders; baseline physical functional ability and depressive symptoms. Competing risk regression models determined the rate of cardiovascular mortality, adjusting for similar confounders and using the total sample only. RESULTS: Spinal pain was associated with an increased rate of all-cause mortality, hazard ratio (HR): 1.13 [95% confidence interval (CI): 1.06-1.21]. There was no association between spinal pain and cardiovascular disease mortality, sub-distribution hazard ratio (SHR): 1.08 [95% CI 0.96-1.21]. After adjusting for confounders (physical functional ability and depressive symptoms), the association became non-significant. All intra-pair analyses were statistically non-significant, although greater in magnitude for monozygotic twins. CONCLUSIONS: Older people reporting spinal pain have 13% increased risk of mortality per years lived but the connection is not causal. We found no association between spinal pain and cardiovascular-specific mortality. The influence of shared familial factors is unlikely. SIGNIFICANCE: Older people reporting spinal pain have 13% increased risk of mortality per year lived. However, this association is not likely to be causal, with the relevant confounders contributing to this relationship. Thus, pain in the spine may be part of a pattern of poor health, which increases mortality risk in the older population.

Risk factors for lymphoedema in women with breast cancer: A large prospective cohort.

A prospective study was conducted to identify women at increased risk for lymphoedema (LE) based on axillary surgery. Assessment occurred prior to surgery, within 4 weeks, and at 6, 12 and 18 months following surgery. Following post-surgery assessment, women were asked to complete weekly diaries regarding events that occurred in the previous week. Risk factors were grouped into demographic, lifestyle, breast cancer treatment-related, arm swelling-related, and post-surgical activities. Bioimpedance spectroscopy thresholds were used to determine presence of LE. At 18-months, 241 women with <5 nodes removed and 209 women with ≥5 nodes removed were assessed. For those with <5 nodes removed, LE was present in 3.3% compared with 18.2% for those with ≥5 nodes removed. There were insufficient events to identify risk factors for those with <5 nodes removed; for those with >5 nodes removed, independent risk factors included presence of arm swelling at 12-months (Odds Ratio (OR): 13.5, 95% CI 4.8, 38.1; P < 0.01), at 6-months (5.6 (2.0, 16.9); P < 0.01), and radiotherapy to the axilla (2.6 (0.7, 8.9); P = 0.14). Arm swelling at 6 and 12 months was associated with taxane-based chemotherapy, high body weight at diagnosis and arm swelling within 4 weeks post-surgery. Of the post-surgical events assessed in a sub-group of women with >5 nodes removed and who maintained weekly diaries, only blood drawn from the 'at-risk' arm was identified as a potential risk (OR 2.0; 0.8, 5.2). For women with ≥5 nodes removed, arm swelling in the first year poses a very strong risk for presence of LE at 18-months.

Patients' perceived level of social isolation affects the prognosis of low back pain.

BACKGROUND: Perceived social isolation is prevalent among patients with low back pain (LBP) and could be a potential prognostic factor for clinical outcomes following an episode of LBP. METHODS: A secondary analysis of an original prospective cohort study, which investigated the validity of the Danish version of the STarT Back Screening Tool (STarT), investigated whether social isolation predicts the clinical outcomes of disability, anxiety, depression and pain catastrophizing in people with LBP. Patients with LBP of any duration (N = 204) from Middelfart, Denmark, were included. Social isolation was measured at baseline using the friendship scale (score ranges from 0 to 24, with lower values meaning higher perceived social isolation), and outcomes were measured at baseline and at 6-month follow-up. Regression models investigated whether social isolation at baseline predicted the outcomes at 6-month follow-up. RESULTS: Some level of social isolation was reported by 39.2% of the participants (n = 80) with 5.9% (n = 12) being very socially isolated. One-point difference on social isolation predicted one point on a 100-point disability scale (adjusted unstandardized coefficient: -0.91; 95% confidence interval (CI): -1.56 to -0.26). Social isolation predicted anxiety; however, a change of one point on the social isolation scale represents a difference of only 0.08 points on a 22-point scale in anxiety (95% CI: 0.01-0.15) and is unlikely to denote clinical importance. Social isolation did not predict pain catastrophizing or depression. CONCLUSIONS: Patients' perceived social isolation predicts disability related to LBP. Further understanding of the role of social isolation in LBP is warranted.

Assessment of breast cancer-related arm lymphedema--comparison of physical measurement methods and self-report.

PURPOSE: To determine the relationship between physical methods of measuring lymphedema and self-reported swelling, their reliability, and standard error of measurement. METHOD: Lymphedema in each arm of women with (n = 33) and without (n = 18) unilateral arm lymphedema, secondary to breast cancer was measured by self-report, bioimpedance spectroscopy (BIS), perometer, and the truncated cone method. RESULTS: The physical measurement tools were highly reliable (ICC((2,1)): 0.94 to 1.00) with high concordance (r(c): 0.89 to 0.99). Self-report correlated moderately with physical measurements (r = 0.65 to 0.71) and was moderately reliable (ICC((2,1)): 0.70). CONCLUSIONS: Lymphedema assessment methods are concordant and reliable but not interchangeable.

Do elite athletes exhibit enhanced proprioceptive acuity, range and strength of knee rotation compared with non-athletes?

The aims of this study were to compare proprioception in knee rotation in Olympic-level soccer players (N=18) with non-athletes (N=18), to explore between-limb differences in soccer players, and examine correlations between proprioception and years of playing, function, physical measures and skill level. The knee rotatory kinaesthetic device was used to present stimuli of different magnitudes to determine proprioceptive acuity for internal and external active rotation, and to measure active and passive rotation range of motion (ROM). Knee rotation strength was measured using a dynamometer. Proprioceptive acuity of the athletes was significantly (P=0.004) better than that of the non-athletes. Athletes displayed significantly less passive ROM (P=0.001), higher isometric muscle strength (P=0.006) and greater hop for distance (P=0.001) than non-athletes. No significant between-limb differences were found in the athletes in any objective outcome measure. Internal rotation proprioceptive acuity was negatively correlated with coach-rated ball skill (r=-0.52) and positively correlated with internal rotation ROM (r=0.59). Our findings suggest that highly trained athletes possess enhanced proprioceptive acuity and muscle strength that may be inherent, or may develop as a result of long-term athletic training.

Single frequency versus bioimpedance spectroscopy for the assessment of lymphedema.

BACKGROUND: The aims were to determine (i) whether single frequency bioimpedance analysis (SFBIA) is as accurate as bioimpedance spectroscopy (BIS) in measurement of extracellular fluid and (ii) whether change in extracellular fluid was specific to only the limb directly affected by surgery. METHODS: Arms of the control (n = 28) and arm lymphedema group (n = 28) and legs of the leg lymphedema group (n = 16) were assessed with SFBIA. All four limbs in all participants were assessed with BIS. All measurements occurred in a single session. RESULTS: BIS-measured ratios were highly concordant with those obtained with SFBIA (r (c) = 0.99, P < 0.001). Repeated measures ANOVA revealed that the ratio involving the lymphedema limb was different to the ratio of the non-oedematous limbs which was not significantly different to the arm or leg ratios of the control group. CONCLUSIONS: SFBIA is a simple accurate alternative to BIS for the clinical assessment of unilateral lymphedema. BIS discriminates those with clinical diagnosis of unilateral lymhoedema from those without the diagnosis.

Effects of rehabilitation after ankle fracture: a Cochrane systematic review.

BACKGROUND: Ankle fracture is one of the most common lower limb fractures. People experience limitations in activities after ankle fracture. OBJECTIVES: The aim of this review was to evaluate the effects of rehabilitation interventions after ankle fracture in adults. METHODS: Electronic databases, reference lists of included studies and relevant systematic reviews, and clinical trials registers were searched for randomised and quasi-randomised controlled trials with adults undergoing any interventions for rehabilitation after ankle fracture. The primary outcomes were activity limitation and adverse events. Two reviewers independently screened search results, assessed methodological quality, and extracted data. RESULTS: Thirty-one studies were included. Clinical and statistical heterogeneity, or the low number of studies in the comparison, prevented meta-analyses in most instances. After surgical fixation, commencing exercise in a removable brace or splint significantly improved activity limitation but also led to a higher rate of adverse events (relative risk 2.61, 95% CI 1.72 to 3.97). Most other rehabilitation interventions did not show an effect in improving activity limitation. CONCLUSIONS: There is limited evidence supporting the use of a removable type of immobilisation and exercise during the immobilisation period for improving activity limitation. Because of the potential increased risk, the patient's ability to comply with this treatment regimen is essential. More clinical trials that are well-designed and adequately-powered are required to strengthen current evidence.

Decreased muscle strength following management of breast cancer.

PURPOSE: To assess whether muscle strength, power and endurance at the affected shoulder were reduced in women treated for breast cancer. Secondly, we assessed whether muscle performance was explained by management or other symptoms. METHODS: Participants were 40 women (mean +/- SD: 56.7 +/- 11.6 yr) who had completed all treatments for breast cancer at least 6 m previously. We measured dynamic concentric strength at one repetition maximum (1RM), endurance at 90% 1RM, and power through a range of 40-100% 1RM for shoulder protractors, extensors and retractors. Strength and endurance, but not power, were measured for shoulder flexors. Additionally, maximal grip strength, passive shoulder range of motion and arm circumference were measured. Self-reported symptoms were recorded using a questionnaire. RESULTS: Shoulder protractors (p = 0.011), retractors (p = 0.007), and extensors (p = 0.009), but not flexors, were significantly weaker on the affected side compared to the unaffected side. Muscle power and endurance at the shoulder and grip strength were not impaired. Inter-limb differences in muscle strength were not explained by the surgical and medical management of the cancer. Self-reported weakness correlated poorly with our measures of muscle strength. CONCLUSIONS: Long-term weakness occurs about the shoulder secondary to treatment for breast cancer. Strategies to prevent weakness need to be considered.

Quality of life of women treated with radiotherapy for breast cancer.

GOALS OF WORK: Radiotherapy is routinely used in the treatment of early breast cancer, particularly in women who have undergone lumpectomy. Its impact on the quality of life of patients is important and is taken into consideration when making informed choices about treatment from both a patient's and health professional's point of view. This study reports on the quality of life of women at baseline, the completion of radiotherapy and 7 months after the completion of radiotherapy. MATERIALS AND METHODS: European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C-30 and BR-23 questionnaires were used to evaluate quality of life of 61 women treated with radiotherapy for breast cancer. Additionally, demographic and treatment variables were analysed in relation to quality of life outcomes to determine if there were any significant predictors of quality of life. MAIN RESULTS: There was no difference in quality of life of women at baseline, completion and 7 months after completion of radiotherapy. Fatigue and breast symptoms increased during radiotherapy but returned to baseline levels at 7 months. Fatigue was the strongest predictor of poor quality of life in women after radiotherapy. CONCLUSION: Women retain a high quality of life and return to baseline function by 7 months after radiotherapy. Treatment may best be targeted to alleviate fatigue and breast symptoms during radiotherapy.

Pectoral stretching program for women undergoing radiotherapy for breast cancer.

Surgery and radiotherapy commonly cause adverse musculoskeletal problems, particularly loss of strength and range of motion, in the upper quadrant of breast cancer patients. Few well-designed studies have investigated whether these impairments can be prevented. Stretching is an effective technique for increasing range of motion, hence the aim of this study was to investigate whether a stretching program reduced acute musculoskeletal impairments in patients undergoing radiotherapy for breast cancer. Sixty-four women were recruited prior to commencement of radiotherapy following breast cancer surgery. Participants were randomised to either a control or stretch group. Participants in both groups were reviewed by the physical therapist on a weekly basis for approximately 6 weeks, and were given general information about skin care and lymphedema. The control group received no advice about exercise. The stretch group received instruction on low-load, prolonged pectoral stretches, which were to be performed daily and were checked at weekly visits. Shoulder range of motion, strength, arm circumference, and quality of life measurements were taken prior to, and at completion of radiotherapy, and at 7 months after radiotherapy. There was no difference in any outcome between groups. Breast symptoms increased for both groups during radiotherapy, without loss of strength or range of movement. The incidence of lymphedema during the study was low for both groups and did not differ between groups. The pectoral stretching program did not influence the outcomes measured because the symptoms reported by patients were not a consequence of contracture.

Design of a knee rotatory kinaesthetic device.

The anterior cruciate ligament (ACL) constrains rotatory motion at the knee and is commonly injured during rotational movements in athletic activity. This densely innervated ligament is assumed to play a role in knee proprioception, however, no study has measured proprioception in a manner relevant to either the kinematics of the ligament or the mechanism of injury, partly because of a lack of suitable equipment. The aims of this technical note are to document the development of a novel knee rotatory kinaesthetic device, and to present details of its construction, reproducibility, accuracy and application. The purpose-built device allows rotational movements at the knee to occur with minimal frictional resistance and provides accurate limits to the magnitude of these movements. This allows analysis of subjects' ability to discriminate between movements of differing magnitudes and thus allows calculation of subjects' sensitivity to small differences in magnitude of active knee rotation. Measurements taken with the device had a high level of agreement with those of a calibrated digital inclinometer (ICC=0.99; 95% CI 0.88 to 0.99) with a mean error of 0.24 degrees . The device also demonstrated excellent reproducibility (Pearson's r=1.0). A single case study is presented to detail the clinical application of the device. This novel device allows subjects to perform active knee rotational movements in a closed kinetic chain with discrete, self-paced movement, enabling calculation of movement discrimination. The device is compact and portable enabling testing to be undertaken in remote settings enhancing its clinical applicability.

Do voluntary strength, proprioception, range of motion, or postural sway predict occurrence of lateral ankle sprain?

Prevention of ankle sprain, the most common sporting injury, is only possible once risk factors have been identified. Voluntary strength, proprioception, postural sway, and range of motion are possible risk factors. A systematic review was carried out to investigate these possibilities. Eligible studies were those with longitudinal design investigating ankle sprain in subjects aged > or = 15 years. The studies had to have measured range of motion, voluntary strength, proprioception, or postural sway before monitoring incidence of lateral ankle sprain. Dorsiflexion range strongly predicted risk of ankle sprain. Postural sway and possibly proprioception were also predictors. Therefore the preliminary evidence suggests that people with reduced ankle dorsiflexion range may be at increased risk of ankle sprain.

Low back pain investigations and prognosis: a review.

Low back pain is reviewed in terms of when investigations are useful and its clinical course. Despite the extensive evaluation of the accuracy of investigations such as radiography, magnetic resonance imaging, and myelography, there is a surprising dearth of research to inform their use in primary care. There is no clear evidence on which to base judgments for selection of appropriate tests to confirm or exclude low back pain pathology. It appears that investigations are rarely necessary for low back pain. Specific investigations should be ordered to identify a particular pathology but should not be ordered routinely for general screening. In the absence of pathology, low back pain and its associated disability improve rapidly in the first weeks after onset, but, in contradiction to all guidelines, both commonly persist and the best evidence suggests that recurrences are common.

Does anterior cruciate ligament reconstruction restore normal knee kinematics?: A prospective MRI analysis over two years.

This prospective study used magnetic resonance imaging to record sagittal plane tibiofemoral kinematics before and after anterior cruciate ligament reconstruction using autologous hamstring graft. Twenty patients with anterior cruciate ligament injuries, performed a closed-chain leg-press while relaxed and against a 150 N load. The tibiofemoral contact patterns between 0 degrees to 90 degrees of knee flexion were recorded by magnetic resonance scans. All measurements were performed pre-operatively and repeated at 12 weeks and two years. Following reconstruction there was a mean passive anterior laxity of 2.1 mm (sd 2.3), as measured using a KT 1000 arthrometer, and the mean Cincinnati score was 90 (sd 11) of 100. Pre-operatively, the medial and lateral contact patterns of the injured knees were located posteriorly on the tibial plateau compared with the healthy contralateral knees (p=0.014), but were no longer different at 12 weeks (p=0.117) or two years postoperatively (p=0.909). However, both reconstructed and healthy contralateral knees showed altered kinematics over time. At two years, the contact pattern showed less posterior translation of the lateral femoral condyle during flexion (p<0.01).

Cutaneous receptors contribute to kinesthesia at the index finger, elbow, and knee.

The neural mechanisms underlying the sense of joint position and movement remain controversial. While cutaneous receptors are known to contribute to kinesthesia for the fingers, the present experiments test the hypothesis that they contribute at other major joints. Illusory movements were evoked at the interphalangeal (IP) joints of the index finger, the elbow, and the knee by stimulation of populations of cutaneous and muscle spindle receptors, both separately and together. Subjects matched perceived movements with voluntary movements of homologous joints on the contralateral side. Cutaneous receptors were activated by stretch of the skin (using 2 intensities of stretch) and vibration activated muscle spindle receptors. Stimuli were designed to activate receptors that discharge during joint flexion. For the index finger, vibration was applied over the extensor tendons on the dorsum of the hand, to evoke illusory metacarpophalangeal (MCP) joint flexion, and skin stretch was delivered around the IP joints. The strong skin stretch evoked the illusion of flexion of the proximal IP joint in 6/8 subjects (12 +/- 5 degrees, mean +/- SE). For the group, strong skin stretch delivered during vibration increased the perceived flexion of the proximal IP joint by eight times with a concomitant decrease in perceived flexion of the MCP joint compared with vibration alone (P < 0.05). For the elbow, vibration was applied over the distal tendon of triceps brachii and skin stretch over the dorsal forearm. When delivered alone, strong skin stretch evoked illusory elbow flexion in 5/10 subjects (9 +/- 4 degrees). Simultaneous strong skin stretch and vibration increased the illusory elbow flexion for the group by 1.5 times compared with vibration (P < 0.05). For the knee, vibration was applied over the patellar tendon and skin stretch over the thigh. Skin stretch alone evoked illusory knee flexion in 3/10 subjects (8 +/- 4 degrees) and when delivered during vibration, perceived knee flexion increased for the group by 1.4 times compared with vibration (P < 0.05). Hence inputs from cutaneous receptors, muscle receptors, and combined inputs from both receptors likely subserve kinesthesia at joints throughout the body.

The detection of human finger movement is not facilitated by input from receptors in adjacent digits.

These experiments were designed to determine whether cutaneous input from a digit provides a general facilitation of the detection of movements applied to an adjacent digit. The ability to detect passive movements at the proximal interphalangeal joint of the right index finger was measured when cutaneous (and joint) input was removed (using local anaesthesia) from the tip of one or both digits adjacent to the test finger (16 subjects). The same parameter was also measured when input was artificially increased by stimulation of the adjacent digits at three intensities: below, above and at perceptual threshold (PT; 15 subjects). Detection of flexion or extension movements was not altered by anaesthesia of one or both adjacent digits. Since it was possible that too few tonically active afferents in the hand had been blocked to reveal an effect, the median nerve was blocked, with movements applied to the little finger, causing no measurable impairment in acuity (three subjects). Simultaneous electrical stimulation of the tips of the adjacent digits at intensities above PT impaired movement detection, but had no effect when delivered at or below PT. To test whether the effect of detectable electrical stimuli was due to a specific interaction between the artificial input and the input evoked by moving the digit, or due to mental distraction, stimuli were delivered above PT to either the left or right little finger, or the test index finger during movement of the index finger. Electrical stimulation of the index finger significantly reduced detection by approximately 50%, but stimulation of the remote little fingers did not. Electrical stimulation is a non-natural stimulus, so a "natural" stimulus was applied by continuously stroking the tips of the adjacent digits with a brush (10 subjects). The natural stimulus also significantly reduced movement detection by approximately 50%. Together, these findings suggest that tonic inputs from digital nerve afferents adjacent to, or more remote from the passively moved finger do not facilitate movement detection. However, the reduced detection during stimulation of the adjacent digits shows that there is nevertheless some interaction between the various proprioceptive inputs from the digits.

Causes of complications from cervical spine manipulation.

Cervical manipulation occasionally causes serious vertebrobasilar complications. The usual cause is vertebral artery dissection, however in some cases there has been no obvious arterial injury. The present paper reviews the mechanisms by which complications occur, particularly when the applied force is trivial or there is no injury to the vertebral arteries, and the factors that increase risk of complications. In addition, implications are drawn for use of the recently revised Australian Physiotherapy Association (APA) guidelines. In the absence of vertebral artery rupture, complications are proposed to arise from vasospasm, haemostasis, endothelial injury or turbulent flow. These mechanisms have a sound scientific basis but have yet to be demonstrated as specifically causing vertebrobasilar complications. The most important risk factors for vertebrobasilar complications appear to be prior trauma to the vertebral arteries and symptoms of vertebrobasilar ischaemia from previous manipulation. There is weak evidence that hypoplasia of the vertebral arteries also increases the risk of complications. Neither general vascular factors nor pre-existing degenerative conditions of the cervical spine increase risk of vertebrobasilar complications. The procedures described in the APA guidelines test adequacy of total cerebral perfusion during cervical movements rather than patency of the vertebral arteries or their susceptibility to injury. The guidelines may therefore indicate potential for surviving a complication from manipulation. They may also identify patients at risk of complications from minor trauma. It is recommended that the procedures described in the APA guidelines be applied prior to every manipulation, and that manipulation be avoided in the presence of any signs of vertebrobasilar insufficiency.

Sensory integration in the perception of movements at the human metacarpophalangeal joint.

These experiments were designed to investigate illusions of movements of the fingers produced by combined feedback from muscle spindle receptors and receptors located in different regions of the skin of the hand. Vibration (100 Hz) applied in cyclic bursts (4 s 'on', 4 s 'off') over the tendons of the finger extensors of the right wrist produced illusions of flexion-extension of the fingers. Cutaneous receptors were activated by local skin stretch and electrical stimulation. Illusory movements at the metacarpophalangeal (MCP) joints were measured from voluntary matching movements made with the left hand. Localised stretch of the dorsal skin over specific MCP joints altered vibration-induced illusions in 8/10 subjects. For the group, this combined stimulation produced movement illusions at MCP joints under, adjacent to, and two joints away from the stretched region of skin that were 176 +/- 33, 122 +/- 9 and 67 +/- 11 % of the size of those from vibration alone, respectively. Innocuous electrical stimulation over the same skin regions, but not at the digit tips, also 'focused' the sensation of movement to the stimulated digit. Stretch of the dorsal skin and compression of the ventral skin around one MCP joint altered the vibration-induced illusions in all subjects. The illusions became more focused, being 295 +/- 57, 116 +/- 18 and 65 +/- 7 % of the corresponding vibration-induced illusions at MCP joints that were under, adjacent to, and two joints away from the stimulated regions of skin, respectively. These results show that feedback from cutaneous and muscle spindle receptors is continuously integrated for the perception of finger movements. The contribution from the skin was not simply a general facilitation of sensations produced by muscle receptors but, when the appropriate regions of skin were stimulated, movement illusions were focused to the joint under the stimulated skin. One role for cutaneous feedback from the hand may be to help identify which finger joint is moving.

Lumbar spine traction: evaluation of effects and recommended application for treatment.

Despite the widespread use of traction, little is known of the mode of effect, and application remains largely anecdotal. The efficacy of traction is also unclear because of generally poor design of the clinical trials to date, and because subgroups of patients most likely to benefit have not been specifically studied. These observations prompted this review, the purposes of which are to evaluate the mechanisms by which traction may provide benefit and to provide rational guidelines for the clinical application of traction. Traction has been shown to separate the vertebrae and it appears that large forces are not required. Vertebral separation could provide relief from radicular symptoms by removing direct pressure or contact forces from sensitised neural tissue. Other mechanisms proposed to explain the effects of traction (e.g. reduction of disc protrusion or altered intradiscal pressure) have been shown not to occur. We conclude that traction is most likely to benefit patients with acute (less than 6 weeks' duration) radicular pain with concomitant neurological deficit. The apparent lack of a dose-response relationship suggests that low doses are probably sufficient to achieve benefit.