Longitudinal excursion and strain in the median nerve during novel nerve gliding exercises for carpal tunnel syndrome

The effectiveness of neural mobilizations in the treatment of musculoskeletal conditions: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

The objective of this review is to identify the effectiveness of neural mobilization techniques in various neuro-musculoskeletal conditions. Outcomes will be analyzed in terms of subgroups such as low back pain, cervico-brachial pain and carpal tunnel syndrome.

BACKGROUND

Musculoskeletal disorders were ranked as the second largest contributor to disability worldwide in a study on the global burden of disease. Low back pain and neck pain contributed to 70% of disability in this comprehensive population-based study. Low back pain and neck pain are multifactorial, with heterogeneous populations. It has been proposed that targeting subgroups of patients may result in better treatment outcomes. Neck pain associated with upper limb pain is prevalent. These patients are more disabled than patients with neck pain alone. Similarly, low back pain with leg pain is a common phenomenon and is acknowledged as a predictor for chronicity.Neuropathic pain is often associated with musculoskeletal complaints including low back pain, whiplash associated disorders (WAD) and acute or chronic radiculopathy, and can be a feature of syndromes such as cervico-brachial pain syndrome. According to the International Association for the Study of Pain, neuropathic pain can be described as "pain caused by a lesion or disease of the somatosensory nervous system." Leg pain associated with back pain can be caused by central sensitization, denervation, nerve sensitization or somatically referred pain. In patients with WAD, neck pain is the most common symptom, but upper limb pain, weakness, paraesthesia and anesthesia are often present. Other conditions in which neural tissue is thought to contribute to the clinical picture are, for instance, lateral epicondalalgia and carpal tunnel syndrome.Management strategies for back pain and neck pain are often multimodal. However, the evidence for effective treatment of nerve related pain is lacking. Neural mobilizations are often used to affect the neural structures in conditions with signs of neural involvement or neural mechano-sensitivity. Neural mobilizations are defined as interventions aimed at affecting the neural structures or surrounding tissue (interface) directly or indirectly through manual techniques or exercise. Neural mobilizations have been studied in various populations such as low back pain, carpal tunnel syndrome, lateral epicondalalgia and cervico-brachial pain. Neural mobilization techniques studied include cervical lateral glides for cervico-brachial pain, nerve gliding exercises for the treatment of carpal tunnel syndrome, cervical lateral glides for lateral epicondalalgia and the slump as a neural mobilization technique in the treatment of low back pain. No specialized equipment is needed in the performance of neural mobilization techniques, which contributes to its popularity.Neural mobilization is said to affect the axoplasmic flow, movement of the nerve and its connective tissue and the circulation of the nerve by alteration of the pressure in the nervous system and dispersion of intraneural oedema. Neural mobilization decreases the excitability of dorsal horn cells. Neural mobilizations can be performed in various ways using passive movement, manual mobilization of the nerve or interface, and exercise. The aim of neural mobilization is to restore the mechanical and neurophysiological function of the nerve.Only one systematic review on the effectiveness of neural mobilizations could be identified in the literature. Since this review, several more studies have been published on this subject. The authors hypothesize that a review of the more recent literature (2008-2014) may confirm positive support for the use of neural mobilizations for neuro-musculoskeletal complaints as previously seen by Ellis and Hing. This review aims to include a meta-analysis and subgrouping of conditions which will be an extension of the previous review by Ellis and Hing. The outcomes of this systematic review may be used to inform clinical practice and the development of best practice guidelines.

Excursion of the Sciatic Nerve During Nerve Mobilization Exercises: An In Vivo Cross-sectional Study Using Dynamic Ultrasound Imaging

STUDY DESIGN

Controlled laboratory cross-sectional study using single-group, within-subject comparisons.

OBJECTIVES

To determine whether different types of neurodynamic techniques result in differences in longitudinal sciatic nerve excursion.

BACKGROUND

Large differences in nerve biomechanics have been demonstrated for different neurodynamic techniques for the upper limb (median nerve), but recent findings for the sciatic nerve have only revealed small differences in nerve excursion that may not be clinically meaningful.

METHODS

High-resolution ultrasound imaging was used to quantify longitudinal sciatic nerve movement in the thigh of 15 asymptomatic participants during 6 different mobilization techniques for the sciatic nerve involving the hip and knee. Healthy volunteers were selected to demonstrate normal nerve biomechanics and to eliminate potentially confounding variables associated with dysfunction. Repeated-measures analyses of variance were used to analyze the data.

RESULTS

The techniques resulted in markedly different amounts of nerve movement (P<.001). The tensioning technique was associated with the smallest excursion (mean ± SD, 3.2 ± 2.1 mm; P < or = .004). The sliding technique resulted in the largest excursion (mean ± SD, 17.0 ± 5.2 mm; P<.001), which was approximately 5 times larger than that resulting from the tensioning technique and, on average, twice as large as that resulting from individual hip or knee movements.

CONCLUSION

Consistent with current theories and findings for the median nerve, different neurodynamic exercises for the lower limb resulted in markedly different sciatic nerve excursions. Considering the continuity of the nervous system, the movement and position of adjacent joints have a large impact on nerve biomechanics.

Ultrasonographic median nerve changes under tendon gliding exercise in patients with carpal tunnel syndrome and healthy controls

STUDY DESIGN

Case control study.

PURPOSE OF THE STUDY

To evaluate the ultrasonographic median nerve changes under tendon gliding exercise in patients with carpal tunnel syndrome (CTS) and healthy controls.

METHODS

Seventy-three patients with CTS and 53 healthy volunteers were consecutively recruited. Each subject underwent a physical examination, nerve conduction studies and ultrasonographic examinations of the median nerve during tendon gliding exercises.

RESULTS

Significant changes in the cross-sectional area of the median nerve were found while moving from the straight position to the hook position and from the hook position to the fist position. There were also significant changes in the flattening ratio when moving from the hook position to the fist position.

CONCLUSIONS

Ultrasonography revealed that the median nerve was compressed in the fist position in both CTS patients and healthy volunteers. Thus, forceful grasping should be avoided during tendon gliding exercises performed in the fist position.

LEVEL OF EVIDENCE

3b.

Results of an Active Neurodynamic Mobilization Program in Patients With Fibromyalgia Syndrome: A Randomized Controlled Trial

OBJECTIVE

To examine the effects of an active neurodynamic mobilization program on pain, neurodynamics, perceived health state, and fatigue in patients with fibromyalgia syndrome (FMS).

DESIGN

Randomized controlled trial.

SETTING

Local fibromyalgia association.

PARTICIPANTS

Patients with FMS (N=48).

INTERVENTIONS

Patients were randomly allocated to an active neurodynamic mobilization program or a control group. The intervention was performed twice a week.

MAIN OUTCOME MEASURES

Pain was assessed with the Brief Pain Inventory and Pain Catastrophizing Scale; neurodynamics were evaluated using neurodynamic tests for upper and lower limbs. The functional state was evaluated with the Health Assessment Questionnaire Disability Index, and perceived fatigue was evaluated with the Fatigue Severity Scale.

RESULTS

Significant (P<.05) between-groups differences were found in the values of pain, upper and lower limb neurodynamics, functional state, and fatigue. Also, significant pre- to postintervention within-group differences were found in the intervention group, whereas no significant changes were found in the control group.

CONCLUSIONS

A neurodynamic mobilization program is effective in improving pain, neurodynamics, functional status, and fatigue in patients with FMS.

The effect of neural mobilisation on cervico-brachial pain: design of a randomised controlled trial

BACKGROUND

Neck pain is a common musculoskeletal complaint and is often associated with shoulder or arm pain. There is a paucity of information on effective treatment for neck and arm pain, such as radiculopathy or cervico-brachial pain. Guidelines recommend neck mobilisation/ manipulation, exercises and advice as the treatment for neck pain, and neck and arm pain. There are a few studies that have used neural mobilisation as the treatment for cervico-brachial pain. Although results seem promising the studies have small sample sizes that make it difficult to draw definite conclusions.

METHODS

A randomised controlled trial will be used to establish the effect of neural mobilisation on the pain, function and quality of life of patients with cervico-brachial pain. Patients will be recruited in four physiotherapy private practices and randomly assigned to usual care or usual care plus neural mobilisation.

DISCUSSION

In clinical practice neural mobilisations is commonly used for cervico-brachial pain. Although study outcomes seem promising, most studies have small participant numbers. Targeting the neural structures as part of the management plan for a subgroup of patients with nerve mechano-sensitivity seems feasible. Patients with neuropathic pain and psychosocial risk factors such as catastrophising, respond poorly to treatment. Although a recent study found these patients less likely to respond to neural mobilisation, the current study will be able to assess whether neural mobilisation has any added benefit compared to usual care. The study will contribute to the knowledge base of treatment of patients with cervico-brachial pain. The findings of the study will be published in an appropriate journal.

TRIAL REGISTRATION

TRIAL REGISTRATION NUMBER

PACTR201303000500157.

Quantitative in vivo longitudinal nerve excursion and strain in response to joint movement: A systematic literature review

BACKGROUND

Neural system mobilization is widely used in the treatment of several painful conditions. Data on nerve biomechanics is crucial to inform the design of mobilization exercises. Therefore, the aim of this review is to characterize normal nervous system biomechanics in terms of excursion and strain.

METHODS

Studies were sought from Pubmed, Physiotherapy Evidence Database, Cochrane Library, Web of Science and Scielo. Two reviewers' screened titles and abstracts, assessed full reports for potentially eligible studies, extracted information on studies' characteristics and assessed its methodological quality.

FINDINGS

Twelve studies were included in this review that assessed the median nerve (n=8), the ulnar nerve (n=1), the tibial nerve (n=1), the sciatic nerve (n=1) and both the tibial and the sciatic nerves (n=1). All included studies assessed longitudinal nerve excursion and one assessed nerve strain. Absolute values varied between 0.1mm and 12.5mm for median nerve excursion, between 0.1mm and 4.0mm for ulnar nerve excursion, between 0.7 mm and 5.2mm for tibial nerve excursion and between 0.1mm and 3.5mm for sciatic nerve excursion. Maximum reported median nerve strain was 2.0%.

INTERPRETATION

Range of motion for the moving joint, distance from the moving joint to the site of the lesion, position of adjacent joints, number of moving joints and whether joint movement stretches or shortens the nerve bed need to be considered when designing neural mobilization exercises as all of these factors seem to have an impact on nerve excursion.

A regional interdependence model of musculoskeletal dysfunction: research, mechanisms, and clinical implications

The term 'regional interdependence' or RI has recently been introduced into the vernacular of physical therapy and rehabilitation literature as a clinical model of musculoskeletal assessment and intervention. The underlying premise of this model is that seemingly unrelated impairments in remote anatomical regions of the body may contribute to and be associated with a patient's primary report of symptoms. The clinical implication of this premise is that interventions directed at one region of the body will often have effects at remote and seeming unrelated areas. The formalized concept of RI is relatively new and was originally derived in an inductive manner from a variety of earlier publications and clinical observations. However, recent literature has provided additional support to the concept. The primary purpose of this article will be to further refine the operational definition for the concept of RI, examine supporting literature, discuss possible clinically relevant mechanisms, and conclude with a discussion of the implications of these findings on clinical practice and research.

The management of digital nerve injuries

A tension-free coaptation is a key factor for the successful outcome of any nerve repair. A variety of host factors influence the outcome of digital nerve repair more than the type of repair per se. Although autologous graft remains the reference standard for reconstruction of any critical digital nerve defect, allografts and conduits have assumed an increasing role.

Altered median nerve deformation and transverse displacement during wrist movement in patients with carpal tunnel syndrome

RATIONALE AND OBJECTIVES

Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. Strong pinch or grip with wrist flexion has been considered a risk factor for CTS. Studying median nerve displacement during wrist movements may provide useful information about median nerve kinematic changes in patients with CTS. The purpose of this study was to evaluate the deformability and mobility of the median nerve in patients with CTS compared to healthy subjects.

MATERIALS AND METHODS

Dynamic ultrasound images were obtained in 20 affected wrists of 13 patients with CTS. Results were compared to complementary data obtained from both wrists of 10 healthy subjects reported in a previous study. Shape and position of initial and final median nerve were measured and analyzed for six defined wrist movements. The deformation ratios for each movement were defined as the median nerve area, perimeter, and circularity of the final position normalized by respective values assessed in the initial position. The median nerve displacement vector and magnitude were also calculated.

RESULTS

The deformation ratio for circularity was significantly less in patients with CTS compared to healthy subjects during wrist flexion (P < .05). The mean vector of median nerve displacement during wrist flexion was significantly different between patients with CTS and healthy subjects (P < .05). The displacement magnitude of the median nerve was found to be less in patients with CTS compared to healthy subjects during most movements, with the exception of wrist extension with fingers extended.

CONCLUSIONS

Patients with CTS differ from normal subjects with regard to mobility and deformability of the median nerve.

Transverse ultrasound assessment of median nerve deformation and displacement in the human carpal tunnel during wrist movements

The symptoms of carpal tunnel syndrome, a compression neuropathy of the median nerve at the wrist, are aggravated by wrist motion, but the effect of these motions on median nerve motion are unknown. To better understand the biomechanics of the abnormal nerve, it is first necessary to understand normal nerve movement. The purpose of this study was to evaluate the deformation and displacement of the normal median nerve at the proximal carpal tunnel level on transverse ultrasound images during different wrist movements, to have a baseline for comparison with abnormal movements. Dynamic ultrasound images of both wrists of 10 asymptomatic volunteers were obtained during wrist maximal flexion, extension and ulnar deviation. To simplify the analysis, the initial and final shape and position of the median nerve were measured and analyzed. The circularity of the median nerve was significantly increased and the aspect ratio and perimeter were significantly decreased in the final image compared with the first image during wrist flexion with finger extension, wrist flexion with finger flexion and wrist ulnar deviation with finger extension (p < 0.01). There were significant differences in median nerve displacement vector between finger flexion, wrist flexion with finger extension and wrist ulnar deviation with finger extension (all p's < 0.001). The mean amplitudes of median nerve motion in wrist flexion with finger extension (2.36 ± 0.79 normalized units [NU]), wrist flexion with finger flexion (2.46 ± 0.84 NU) and wrist ulnar deviation with finger extension (2.86 ± 0.51 NU) were higher than those in finger flexion (0.82 ± 0.33 NU), wrist extension with finger extension (0.77 ± 0.46 NU) and wrist extension with finger flexion (0.81 ± 0.58 NU) (p < 0.0001). In the normal carpal tunnel, wrist flexion and ulnar deviation could induce significant transverse displacement and deformation of the median nerve.

Histopathological changes in the periphery of the sciatic nerve of rats after knee joint immobilization

[Purpose] This study was performed to investigate the histological changes that occur in the periphery of the sciatic nerve in rats undergoing knee immobilization. [Subjects and Methods] 29 male 9-week-old Wistar rats were divided randomly into a control group (C group, n = 7) and an immobilized group (I group, n = 22). The animals in the I group had the left knee joint immobilized in maximal flexion with plaster casts for two weeks. After the experimental period, we obtained cross-sections of tissues from the center of the left thigh, and the periphery of the sciatic nerve was observed under an optical microscope after hematoxylin-eosin staining. [Results] In contrast to the rats of C group, the rats in I group showed adherence between the bundle of nerve fibers and perineurium, as well as thickening of the perineurium. These histological changes were statistically significant. [Conclusions] Immobilization of the knee joints of rats resulted in characteristic histological changes in the connective tissue around the sciatic nerve.

The efficacy of manual joint mobilisation/manipulation in treatment of lateral ankle sprains: a systematic review

BACKGROUND

Lateral ankle sprains are common and can have detrimental consequences to the athlete. Joint mobilisation/manipulation may limit these outcomes.

OBJECTIVE

Systematically summarise the effectiveness of manual joint techniques in treatment of lateral ankle sprains.

METHODS

This review employed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A computer-assisted literature search of MEDLINE, CINHAL, EMBASE, OVID and Physiotherapy Evidence Database (PEDro) (January 1966 to March 2013) was used with the following keywords alone and in combination 'ankle', 'sprain', 'injuries', 'lateral', 'manual therapy', and 'joint mobilisation'. The methodological quality of individual studies was assessed using the PEDro scale.

RESULTS

After screening of titles, abstracts and full articles, eight articles were kept for examination. Three articles achieved a score of 10 of 11 total points; one achieved a score of 9; two articles scored 8; one article scored a 7 and the remaining article scored a 5. Three articles examined joint techniques for acute sprains and the remainder examined subacute/chronic ankle sprains. Outcome measures included were pain level, ankle range of motion, swelling, functional score, stabilometry and gait parameters. The majority of the articles only assessed these outcome measures immediately after treatment. No detrimental effects from the joint techniques were revealed in any of the studies reviewed.

CONCLUSIONS

For acute ankle sprains, manual joint mobilisation diminished pain and increased dorsiflexion range of motion. For treatment of subacute/chronic lateral ankle sprains, these techniques improved ankle range-of-motion, decreased pain and improved function.

Massage therapy as an effective treatment for carpal tunnel syndrome

Carpal tunnel syndrome is a common peripheral entrapment that causes neuralgia in the median nerve distribution of the hand. The primary aim of this study was to evaluate the efficacy of massage therapy as a treatment for carpal tunnel syndrome. Within this process, the locations of trigger-points that refer neuropathy to the hand were identified. The creation of massage pressure tables provides a means of treatment reproducibility. Twenty-one participants received 30 min of massage, twice a week, for six weeks. Carpal tunnel questionnaires, the Phalen, Tinel, and two-point discrimination tests provided outcome assessment. The results demonstrated significant (p < 0.001) change in symptom severity and functional status from two weeks. Based on this study, the combination of massage and trigger-point therapy is a viable treatment option for carpal tunnel syndrome and offers a new treatment approach.

The effects of neurodynamic mobilization on fluid dispersion within the tibial nerve at the ankle: an unembalmed cadaveric study

OBJECTIVE

To evaluate the effects of neurodynamic mobilization on the fluid dynamics of the tibial nerve in cadavers.

BACKGROUND

Evidence showing patients benefit from neural mobilization is limited. Mechanisms responsible for changes in patient symptoms are unclear.

METHODS

Bilateral lower limbs of six unembalmed cadavers (n = 12) were randomized into matched pairs and dissected to expose the tibial nerve proximal to the ankle. Dye composed of Toulidine blue and plasma was injected into the nerve. The longitudinal dye spread was measured pre- and post-mobilization. The experimental group received the intervention consisting of 30 repetitions of passive ankle range of motion over the course of 1 minute. The matched control limb received no mobilization. Data were analysed using a 2×2 repeated measures ANOVA with subsequent t-tests for pairwise comparisons.

RESULTS

Mean dye spread was 23.8±10.2 mm, a change of 5.4±4.7% in the experimental limb as compared to 20.7±6.0 mm, a change of -1.5±3.9% in the control limb. The ANOVA was significant (P⩽0.02) for interaction between group (experimental/control) and time (pre-mobilization/post-mobilization). t-test results were significant between pre- and post-mobilization of the experimental leg (P = 0.01), and between control and experimental limbs post-mobilization (P⩽0.02).

CONCLUSION

Passive neural mobilization induces dispersion of intraneural fluid. This may be clinically significant in the presence of intraneural edema found in pathological nerves such as those found in compression syndromes.

Interventions in the disturbances in the motor and sensory environment

Treatment of peripheral nervous system (PNS) pathology presents intervention challenges to every therapist. Many of the current and future interventions will be directed at restoring the normal anatomy, function, and biomechanical properties of the PNS, restoring normal neural physiology and ultimately patient function and quality of life. Present interventions use mechanical (movement) or electrical procedures to affect various properties of the peripheral nerve. The purpose of this article was to apply basic science to clinical practice. The pathology and accompanying structural and biomechanical changes in the PNS will be presented in three specific areas commonly encountered in the clinic: nerve injury and laceration; compression neuropathies; and neuropathic pain and neural tension dysfunction. The intent is to address possible interventions exploring the clinical reasoning process that combines basic science and evidence-based best practice. The current lack of literature to support any one intervention requires a strong foundation and understanding of the PNSs' structure and function to refine current and develop new intervention strategies. Current evidence will be presented and linked with future considerations for intervention and research. During this interlude of development and refinement, best practice will rely on sound clinical reasoning skills that incorporate basic science to achieve a successful outcome when treating these challenging patients.

Comparison of longitudinal sciatic nerve movement with different mobilization exercises: an in vivo study utilizing ultrasound imaging

STUDY DESIGN

Controlled laboratory study using a single-group, within-subjects comparison.

OBJECTIVES

To determine whether different types of neural mobilization exercises are associated with differing amounts of longitudinal sciatic nerve excursion measured in vivo at the posterior midthigh region.

BACKGROUND

Recent research focusing on the upper limb of healthy subjects has shown that nerve excursion differs significantly between different types of neural mobilization exercises. This has not been examined in the lower limb. It is important to initially examine the influence of neural mobilization on peripheral nerve excursion in healthy people to identify peripheral nerve excursion impairments under conditions in which nerve excursion may be compromised.

METHODS

High-resolution ultrasound imaging was used to assess sciatic nerve excursion at the posterior midthigh region. Four different neural mobilization exercises were performed in 31 healthy participants. These neural mobilization exercises used combinations of knee extension and cervical spine flexion and extension. Frame-by-frame cross-correlation analysis of the ultrasound images was used to calculate nerve excursion. A repeated-measures analysis of variance and isolated means comparisons were used for data analysis.

RESULTS

Different neural mobilization exercises induced significantly different amounts of sciatic nerve excursion at the posterior midthigh region (P<.001). The slider exercise, consisting of the participant performing simultaneous cervical spine and knee extension, resulted in the largest amount of sciatic nerve excursion (mean ± SD, 3.2 ± 2.0 mm). The amount of excursion during the slider exercise was slightly greater (mean ± SD, 2.6 ± 1.5 mm; P = .002) than it was during the tensioner exercise (simultaneous cervical spine flexion and knee extension). The single-joint neck flexion exercise resulted in the least amount of sciatic nerve excursion at the posterior midthigh (mean ± SD, -0.1 ± 0.1 mm), which was significantly smaller than the other 3 exercises (P<.001).

CONCLUSION

These findings are consistent with the results of previous research that has examined median nerve excursion associated with different neural mobilization exercises. Such nerve excursion supports theories of nerve motion associated with cervical spine and extremity movement, as generalizable to the lower limb.

Effect of splinting and exercise on intraneural edema of the median nerve in carpal tunnel syndrome--an MRI study to reveal therapeutic mechanisms

Splinting and nerve and tendon gliding exercises are commonly used to treat carpal tunnel syndrome (CTS). It has been postulated that both modalities reduce intraneural edema. To test this hypothesis, 20 patients with mild to moderate CTS were randomly allocated to either night splinting or a home program of nerve and tendon gliding exercises. Magnetic resonance images of the wrist were taken at baseline, immediately after 10 min of splinting or exercise, and following 1 week of intervention. Primary outcome measures were signal intensity of the median nerve at the wrist as a measure of intraneural edema and palmar bowing of the carpal ligament. Secondary outcome measures were changes in symptom severity and function. Following 1 week of intervention, but not immediately after 10 min, signal intensity of the median nerve was reduced by ≈ 11% at the radioulnar level for both interventions (p = 0.03). This was accompanied by a mild improvement in symptoms and function (p < 0.004). A similar reduction in signal intensity is not observed in patients who only receive advice to remain active. No changes in signal intensity were identified further distally (p > 0.28). Ligament bowing remained unchanged (p > 0.08). Intraneural edema reduction is a likely therapeutic mechanism of splinting and exercise.

The validity of upper-limb neurodynamic tests for detecting peripheral neuropathic pain

The validity of upper-limb neurodynamic tests (ULNTs) for detecting peripheral neuropathic pain (PNP) was assessed by reviewing the evidence on plausibility, the definition of a positive test, reliability, and concurrent validity. Evidence was identified by a structured search for peer-reviewed articles published in English before May 2011. The quality of concurrent validity studies was assessed with the Quality Assessment of Diagnostic Accuracy Studies tool, where appropriate. Biomechanical and experimental pain data support the plausibility of ULNTs. Evidence suggests that a positive ULNT should at least partially reproduce the patient's symptoms and that structural differentiation should change these symptoms. Data indicate that this definition of a positive ULNT is reliable when used clinically. Limited evidence suggests that the median nerve test, but not the radial nerve test, helps determine whether a patient has cervical radiculopathy. The median nerve test does not help diagnose carpal tunnel syndrome. These findings should be interpreted cautiously, because diagnostic accuracy might have been distorted by the investigators' definitions of a positive ULNT. Furthermore, patients with PNP who presented with increased nerve mechanosensitivity rather than conduction loss might have been incorrectly classified by electrophysiological reference standards as not having PNP. The only evidence for concurrent validity of the ulnar nerve test was a case study on cubital tunnel syndrome. We recommend that researchers develop more comprehensive reference standards for PNP to accurately assess the concurrent validity of ULNTs and continue investigating the predictive validity of ULNTs for prognosis or treatment response.

Measurement of tibial nerve excursion during ankle joint dorsiflexion in a weight-bearing position with ultrasound imaging

BACKGROUND

The ability of peripheral nerves to stretch and slide is thought to be of paramount importance to maintain ideal neural function. Excursion in peripheral nerves such as the tibial can be measured by analysis of ultrasound images. The aim of this study was to assess the degree of longitudinal tibial nerve excursion as the ankle moved from plantar flexion to dorsiflexion in a standardised weight-bearing position. The reliability of ultrasound imaging to measure tibial nerve excursion was also quantified.

METHODS

The tibial nerve was imaged over two separate sessions in sixteen asymptomatic participants in a weight-bearing position. Longitudinal nerve excursion was calculated from a three-second video loop captured by ultrasound imaging using frame-by-frame cross-correlation analysis. Intraclass correlation coefficients (ICC) with 95% confidence intervals (CI) were used to assess the intra-rater reliability. Standard error of the measurement (SEM) and smallest real difference (SRD) were calculated to assess measurement error.

RESULTS

Mean nerve excursion was 2.99 mm SEM ± 0.22 mm. The SRD was 0.84 mm for session 1 and 0.66 mm for session 2. Intra-rater reliability was excellent with an ICC = 0.93.

CONCLUSIONS

Assessment of real-time ultrasound images of the tibial nerve via frame-by-frame cross-correlation analysis is a reliable non-invasive technique to assess longitudinal nerve excursion. The relationship between foot posture and nerve excursion can be further investigated.

Scientific study of the extent of transverse movement of the median nerve at the wrist during active wrist extension in static positions of the upper limb tension test one

Objective.

Longitudinal glide of the median nerve is affected in typical entrapment neuropathies such as carpal tunnel syndrome. The upper limb tension test one (ULTT1) is used by clinicians to assess patients’ responses to passive movements that affect the median nerve. ULTT1 is thought to mainly assess the longitudinal glide of the median nerve; however, transverse glide of the nerve at the wrist may be a more sensitive measure of an entrapment neuropathy.

Method.

Sixteen wrists of four male and 11 female healthy volunteers were studied with ultrasound imaging in this small original study. Images were collected in eight different combinations of shoulder, elbow and forearm posture. In each posture the wrist was moved from full flexion to 30° of extension.

Results

Nerve excursion from full wrist flexion to 30° of extension was mainly in a radio-dorsal direction. It ranged from a minimum of 1.8 mm (SD ± 2.0 mm) up to 3.57 mm (SD ± 1.86 mm) of transverse movement, and 0.22 mm (SD ± 0.59 mm) of volar movement to 0.96 mm (SD ± 0.76 mm) of dorsal movement. In all eight of the positions tested, forearm supination led to greater transverse movement of the nerve at the wrist.

Conclusions

Transverse movement of the median nerve is most marked with forearm supination, irrespective of other changes in the kinetic chain. The nerve moves dorsally in all movements except when the forearm flexors are off-loaded in elbow extension and elbow flexion. These findings confirm the transverse movement of the median nerve at the wrist, during active wrist extension within positions of the ULTT, but that the shoulder and elbow position have little impact on the degree of movement.

Tendon and nerve excursion in the carpal tunnel in healthy and CTD wrists

BACKGROUND

During hand and finger motions, friction between flexor digitorum superficialis tendon and the median nerve is thought to play a role in the development of cumulative trauma disorders. This study investigated three methods to determine excursions of the flexor digitorum superficialis tendon and median nerve using several motions.

METHODS

Twenty-five participants (mean age 37.2 years SD 13.4) were classified as healthy (n=16), self-reported distal upper extremity cumulative trauma disorders (6), or wheelchair users (3). Static carpal tunnel measurements were taken and displacements of the index flexor digitorum superficialis tendon and median nerve were determined via the velocity time integral and post hoc integration of the Doppler ultrasound waveform using a 12-5 MHz linear array transducer, as well as using predictive equations.

FINDINGS

Median nerves in symptomatic wrists were larger than healthy wrists by 4.2 mm(2) (left) and 4.1 mm(2) (right) proximally to less than 1.4 mm(2) distally. In healthy wrists, left-right tendon excursion differences ranged from 0.7 mm to 4.3 mm depending on the motion while left to right differences in symptomatic wrists ranged over 22.2 mm. Ultrasound measures of tendon excursion overestimated those determined using predictive equations and were poorly correlated. The ratio of median nerve excursion to tendon excursion was lower in finger only motions compared to wrist motions with or without finger motion.

INTERPRETATION

Spectral Doppler ultrasound imaging provided insights into tendon excursion that was not apparent with mathematical modeling. The difference in excursion between finger motions and wrist motions could be beneficial in therapeutic techniques.

The comparative effectiveness of tendon and nerve gliding exercises in patients with carpal tunnel syndrome: a randomized trial

OBJECTIVE

: The aim of this study was to investigate the effectiveness of tendon and nerve gliding exercises as a part of combined treatments for carpal tunnel syndrome.

DESIGN

: Patients with carpal tunnel syndrome were randomized into three groups. All patients received conventional treatments (splint and paraffin therapy, as in group 3), but group 1 underwent additional tendon gliding exercises and group 2 underwent additional nerve gliding exercises. Each patient received a package of questionnaires and underwent physical examinations and nerve conduction study of the upper limbs before and after treatment for 2 mos.

RESULTS

: Sixty patients were recruited, and 53 completed the study. There were significant improvements in symptom severity and pain scale scores in all groups. However, only group 1 showed significant improvements in their scores on functional status; the Disabilities of the Arm, Shoulder, and Hand questionnaire; and the physical domain of the World Health Organization Quality of Life Questionnaire Brief Version. After adjusting for baseline data, we found significant differences in the functional status scores among the groups. Post hoc analyses detected a significant difference in functional status scores between groups 1 and 2.

CONCLUSIONS

: The combination of tendon gliding exercises with conventional treatments may be more effective than that of nerve gliding exercises with conventional treatments.

Heightened pain sensitivity in individuals with signs and symptoms of carpal tunnel syndrome and the relationship to clinical outcomes following a manual therapy intervention

Neurophysiological responses related to lessening of pain sensitivity are a suggested mechanism of manual therapy. Prior studies have observed generalized lower pain thresholds associated with carpal tunnel syndrome (CTS) in comparison to healthy controls. The present study sought to determine whether similar findings were present in suprathreshold measures and measures specific to central integration of pain (temporal summation and after sensations). Additionally, we wished to determine whether measures of pain sensitivity were related to clinical outcomes in participants with signs and symptoms of CTS receiving a manual therapy intervention. Individuals with signs and symptoms of CTS reported greater pain sensitivity to suprathreshold measures of mechanical pain, temporal summation, and after sensation in comparison to healthy controls. Immediate lessening of mechanical pain sensitivity and after sensations in response to a manual therapy intervention and 3-week attenuation of temporal summation following a 3-week course of manual therapy were associated with 3-week changes in clinical pain intensity in participants with signs and symptoms of CTS. These findings suggest heightened pain sensitivity across several parameters may be associated with CTS. Furthermore, changes in mechanical pain, after sensation, and temporal summation may be related to improvements in clinical outcomes.

Impact of order of movement on nerve strain and longitudinal excursion: a biomechanical study with implications for neurodynamic test sequencing

It is assumed that strain in a nerve segment at the end of a neurodynamic test will be greatest if the joint nearest that nerve segment is moved first in the neurodynamic test sequence. To test this assumption, the main movements of the median nerve biased neurodynamic test were applied in three different sequences to seven fresh-frozen human cadavers. Strain and longitudinal excursion were measured in the median nerve at the distal forearm. Strain and relative position of the nerve at the end of a test did not differ between sequences. The nerve was subjected to higher levels of strain for a longer duration during the sequence where wrist extension occurred first. The pattern of excursion was different for each sequence. The results highlight that order of movement does not affect strain or relative position of the nerve at the end of a test when joints are moved through comparable ranges of motion. When used clinically, different neurodynamic sequences may still change the mechanical load applied to a nerve segment. Changes in load may occur because certain sequences apply increased levels of strain to the nerve for a longer time period, or because sequences differ in ranges of joint motions.

Current concepts of carpal tunnel syndrome: pathophysiology, treatment, and evaluation

The current concepts of carpal tunnel syndrome (CTS) with respect to its pathophysiology, treatment, and evaluation are discussed. With regard to the pathophysiology of idiopathic CTS, biomechanical studies to determine the kinematics of the flexor tendon, and the median nerve inside the carpal tunnel may provide valuable insights. Different degrees of excursion between the flexor tendons and the median nerve could cause strain and microdamage to the synovial tissue; this has been microscopically observed. A biomechanical approach for elucidating the events that trigger the development of CTS seems interesting; however, there are limitations to its applications. Endoscopic carpal tunnel release (ECTR) is a useful technique for achieving median nerve decompression. However, it is not considered superior to conventional open carpal tunnel release in terms of fast recovery of hand function. Unless the effect of inserting a cannula into the diseased carpal tunnel on the median nerve function is quantitatively elucidated, ECTR will not be regarded as a standard procedure for relieving the median nerve from chronic compression. The treatment of CTS should be evaluated on the basis of patient-oriented questionnaires as well as conventional instruments because these questionnaires have been validated and found to be highly responsive to the treatment. It should be noted that nerve conduction studies exclusively evaluate the function of the median nerve, whereas patient-oriented questionnaires take into account not only the symptoms of CTS but other accompanying pathologies as well, such as flexor tenosynovitis. In Japan, the number of CTS patients is expected to rise; this may be attributed to a general increase in the life-span of the Japanese and increase in the number of diabetic patients. Thus, more efforts should be directed toward elucidating the pathophysiology of so-called idiopathic CTS, so that new treatment strategies can be established for CTS of different pathologies.

A randomized sham-controlled trial of a neurodynamic technique in the treatment of carpal tunnel syndrome

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 anatomically stress 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.

Effects of upper extremity neural mobilization on thermal pain sensitivity: a sham-controlled study in asymptomatic participants

STUDY DESIGN

A single-blinded, quasi-experimental, within- and between-sessions assessment.

OBJECTIVES

To investigate potential mechanisms of neural mobilization (NM), using tensioning techniques in comparison to sham NM on a group of asymptomatic volunteers between the ages of 18 and 50.

BACKGROUND

NM utilizing tensioning techniques is used by physical therapists in the treatment of patients with cervical and/or upper extremity symptoms. The underlying mechanisms of potential benefits associated with NM tensioning techniques are unknown.

METHODS AND MEASURES

Participants (n = 62) received either a NM or sham NM intervention 2 to 3 times a week for a total of 9 sessions, followed by a 1-week period of no intervention to assess carryover effects. A-delta (first pain response) and C-fiber (temporal summation) mediated pain perceptions were tested via thermal quantitative sensory testing procedures. Elbow extension range of motion (ROM) and sensory descriptor ratings were obtained during a neurodynamic test for the median nerve. Data were analyzed with repeated-measures analysis of variance (ANOVA).

RESULTS

No group differences were seen for A-delta mediated pain perception at either immediate or carryover times. Group differences were identified for immediate C-fiber mediated pain perception (P = .032), in which hypoalgesia occurred for the NM group but not the sham NM group. This hypoalgesic effect was not maintained at carryover (P = .104). Group differences were also identified for the 3-week and carryover periods for elbow extension ROM (P = .004), and for the participant sensory descriptor ratings (P = .018), in which increased ROM and decreased sensory descriptor ratings were identified in participants in the NM group but not the sham NM group.

CONCLUSION

This study provides preliminary evidence that mechanistic effects of tensioning NM differ from sham NM for asymptomatic participants. Specifically, NM resulted in immediate, but not sustained, C-fiber mediated hypoalgesia. Also, NM was associated with increased elbow ROM and a reduction in sensory descriptor ratings at 3-week and carryover assessment times. These differences provide potentially important information on the mechanistic effects of NM, as well as the description of a sham NM for use in future clinical trials.

Different nerve-gliding exercises induce different magnitudes of median nerve longitudinal excursion: an in vivo study using dynamic ultrasound imaging

STUDY DESIGN

Controlled laboratory study using single-group, within-subject comparisons.

OBJECTIVES

To determine in an in vivo study whether different types of nerve-gliding exercises are associated with different amounts of longitudinal nerve excursion.

BACKGROUND

Different types of nerve-gliding exercises have been proposed. It is assumed that different exercises produce different amounts of excursion and strain in the peripheral nervous system. Although this has been confirmed in cadaveric experiments, in vivo studies are lacking.

METHODS

High-resolution ultrasound was used to measure longitudinal excursion of the median nerve in the upper arm during 6 different nerve-gliding exercises. Nerve mobilization techniques that involved the elbow and neck were evaluated in 15 asymptomatic volunteers (mean +/- SD age, 30 +/- 8 years). Nerve longitudinal excursion was calculated using a frame-by-frame cross-correlation analysis. A repeated-measures analysis of variance was used to analyze the data.

RESULTS

Different exercises induced different amounts of longitudinal nerve excursion (P<.0001). The "sliding technique" was associated with the largest excursion (mean +/- SD, 10.2 +/- 2.8 mm; P = .0001). The amount of nerve movement associated with the "tensioning technique" (mean +/- SD, 1.8 +/- 4.0 mm) was smaller than the nerve excursion induced with individual movements of the neck or elbow (mean +/- SD range, -3.4 +/- 0.9 to 5.6 +/- 2.1 mm; P = .0001).

CONCLUSION

These findings confirm that different types of neurodynamic techniques have different mechanical effects on the nervous system. Recognition of these differences may assist in the selection of treatment techniques. Having demonstrated differences in mechanical effects, future research will have to evaluate whether these different techniques are also associated with different physiological and therapeutic effects.

Shear strain and motion of the subsynovial connective tissue and median nerve during single-digit motion

PURPOSE

The objective of this study was to measure the relative motion of the middle finger flexor digitorum superficialis (FDS) tendon, its adjacent subsynovial connective tissue (SSCT), and the median nerve during single-digit motion within the carpal tunnel in human cadaver specimens and to estimate the relative motions of these structures in different wrist positions.

METHODS

Using fluoroscopy during simulated single-digit flexion, we measured the relative motion of the middle finger FDS tendon, SSCT, and median nerve within the carpal tunnel in 12 human cadavers. Measurements were obtained for 3 wrist positions: neutral, 60 degrees flexion, and 60 degrees extension. After testing with an intact carpal tunnel was completed, the flexor retinaculum was cut with a scalpel, and the same testing procedure was repeated for each wrist position. The relative motions of the tendon, SSCT, and median nerve were compared using a shear index, defined as the ratio of the difference in motion along the direction of tendon excursion between 2 tissues divided by tendon excursion, expressed as a percentage.

RESULTS

Both tendon-SSCT and tendon-nerve shear index were significantly higher in the 60 degrees of wrist flexion and extension positions than in the neutral position. After division of the flexor retinaculum, the shear index in the 60 degrees wrist extension position remained significantly different from that of the neutral position.

CONCLUSIONS

We have found that the relative motion between a tendon and SSCT in the carpal tunnel is maximal at extremes of wrist motion. These positions may predispose the SSCT to shear injury.

The mechanisms of manual therapy in the treatment of musculoskeletal pain: a comprehensive model

Prior studies suggest manual therapy (MT) as effective in the treatment of musculoskeletal pain; however, the mechanisms through which MT exerts its effects are not established. In this paper we present a comprehensive model to direct future studies in MT. This model provides visualization of potential individual mechanisms of MT that the current literature suggests as pertinent and provides a framework for the consideration of the potential interaction between these individual mechanisms. Specifically, this model suggests that a mechanical force from MT initiates a cascade of neurophysiological responses from the peripheral and central nervous system which are then responsible for the clinical outcomes. This model provides clear direction so that future studies may provide appropriate methodology to account for multiple potential pertinent mechanisms.

Effects of carpal tunnel release on the relative motion of tendon, nerve, and subsynovial connective tissue in a human cadaver model

BACKGROUND

The purpose of this study was to evaluate the effect of flexor retinaculum division (simulated carpal tunnel release) on the relative motion of flexor tendon, subsynovial connective tissue, and median nerve in human cadaver specimens.

METHODS

Using fluoroscopy, we measured the relative motion of middle finger flexor digitorum superficialis tendon, subsynovial connective tissue, and median nerve in twelve human cadavers with simulated fist motion. Measurements were obtained for three wrist positions: neutral; 60 degrees flexion; and 60 degrees extension. The shear index was defined as the difference in motion between two tissues (tendon, subsynovial connective tissue, or nerve) relative to tendon excursion, expressed as a percentage. After testing with an intact carpal tunnel, the flexor retinaculum was cut and the testing procedure was repeated.

FINDINGS

With an intact flexor retinaculum, the wrist flexion position showed significantly less displacement for the subsynovial connective tissue and median nerve relative to tendon displacement, and thus the highest potential shear strain between subsynovial connective tissue-tendon, and tendon-nerve. The wrist extension position also had a significantly higher potential shear strain for tendon-nerve compared to the neutral position. After division of the flexor retinaculum, the differences in shear index among wrist positions were reduced. For the wrist flexion position, the subsynovial connective tissue and median nerve displacements significantly increased, indicating lower shear index values.

INTERPRETATION

These findings suggest that division of flexor retinaculum reduces the potential shear strain and thus possibly the risk of shear injury to tissues with the carpal tunnel.

Strain in the Tibial and Plantar Nerves with Foot and Ankle Movements and the Influence of Adjacent Joint Positions

We studied the influence of different positions in neighboring joints on strain in the tibial and plantar nerves during ankle and toe movements. Tibial nerve strain at the ankle was measured during ankle dorsiflexion in ten cadavers; plantar nerve strain was measured during toe extension. Tibial nerve strain increased with ankle dorsiflexion (mean increase: 3.9%) and strain was higher when the nervous system was pretensioned by either knee extension or hip flexion (p ≤ .011). Strain was even higher when the nerve bed was elongated at both the hip and knee (p ≤ .006) before performing dorsiflexion. A similar trend was observed for the plantar nerves with ankle positioning. In conclusion, the change in nerve strain is strongly influenced by positions in neighboring joints. This insight into nerve biomechanics provides a foundation for progressive mobilization exercises for disorders such as tarsal tunnel syndrome.