Effect of ankle dorsiflexion on displacement and strain in the tibial nerve and biceps femoris muscle at the posterior knee during the straight leg raise: Investigation of specificity of nerve movement

Median nerve stiffness with three movement sequences of the upper limb neurodynamic test 1: An ultrasound shear-wave elastography study

BACKGROUND

During the Upper Limb Neurodynamic Test 1 (ULNT1) joint movement order can be varied to improve its diagnostic accuracy. However, nerve behavior with neurodynamic sequences still requires in vivo research.

OBJECTIVE

To quantify differences in median nerve (MN) stiffness measuring shear-wave velocity (SWV) with ultrasound elastography during three sequences of the ULNT1.

DESIGN

Cross-sectional study.

METHODS

MN SWV was measured in 35 asymptomatic subjects at the wrist and elbow at the initial and final position (P1) of the standard (ULNT1-STD), proximal-to-distal (ULNT1-PROX) and distal-to-proximal (ULNT1-DIST) sequences of the ULNT1.

RESULTS

Significantly different increases at P1 in nerve stiffness occurred between sequences and locations (p < 0.001). At the wrist, the ULNT1-PROX produced the smallest increase (44.32% ± 44.06, SWV: 4.49 ± 0.95 m/s), the ULNT1-STD produced a larger increase (82.13% ± 45.36, SWV: 5.67 ± 0.79 m/s, p < 0.001) and the ULNT1-DIST produced the largest (92.90% ± 55.37, SWV: 5.97 ± 0.79 m/s, p < 0.001). Differences between the ULNT1-DIST and ULNT1-STD did not reach significance. At the elbow, the ULNT1-PROX showed a 119.92% ± 53.51 increase (SWV: 4.08 ± 0.84 m/s), the ULNT1-DIST a 134.84% ± 53.83 (SWV: 4.34 ± 0.77 m/s), and the ULNT1-STD a 113.30% ± 59.28 (SWV: 3.98 ± 1.04 m/s). No significant differences were found among the sequences.

CONCLUSION

The ULNT1-STD and ULNT1-DIST showed greater increases at MN stiffness at the wrist compared to the ULNT1-PROX. This supports a basis for future investigation of the mechanisms of neurodynamic testing in which emphasizing anatomical locations for improving diagnostic efficacy might be applied.

Impact of Neurodynamic Sequencing on the Mechanical Behaviour of the Median Nerve and Brachial Plexus: An Ultrasound Shear Wave Elastography Study

BACKGROUND

When performing the Upper Limb Neurodynamic Test 1 (ULNT1), the order of joint movement can be varied to place more stress onto certain nerve segments. However, the mechanisms underlying this phenomenon are still unclear. This study aimed to analyze the differences in the stiffness of the median nerve (MN) and the brachial plexus (BP) using ultrasound shear wave elastography during three sequences of the ULNT1: standard (ULNT1-STD), distal-to-proximal (ULNT1-DIST), and proximal-to-distal (ULNT1-PROX).

METHODS

Shear wave velocity (SWV) was measured at the initial and final position of each sequence at the MN (wrist) and at the C5 and C6 nerve roots (interscalene level) in 31 healthy subjects.

RESULTS

A significant interaction was found between ULNT1 sequence and location (p < 0.001). The ULNT1-STD and ULNT1-DIST induced a greater stiffness increase in the MN (5.67 ± 0.91 m/s, +113.94%; 5.65 ± 0.98 m/s, +115.95%) compared to C5 and C6 (p < 0.001). The ULNT1-PROX resulted in a significantly smaller increase in stiffness at the MN (4.13 ± 0.86 m/s, +54.17%, p < 0.001), but a greater increase at C5 (4.88 ± 1.23 m/s, +53.39%, p < 0.001) and at C6 (4.87 ± 0.81 m/s, +31.55%). The differences for the ULNT1-PROX at C6 were only significant compared to the ULNT1-STD (p < 0.001), but not the ULNT1-DIST (p = 0.066).

CONCLUSIONS

BP and MN stiffness vary depending on the joint movement sequence during neurodynamic testing. However, the influence of the surrounding tissues may have affected SWV measurements; consequently, these results should be interpreted with caution.

Accuracy of the Standard and Distal-to-Proximal Sequence of the Upper Limb Neurodynamic Test 1 for the Diagnosis of Carpal Tunnel Syndrome: The Role of Side-to-Side Comparisons

Background/Objective: This study aimed to evaluate the diagnostic accuracy of two upper limb neurodynamic test 1 (ULNT1) sequences for detecting carpal tunnel syndrome (CTS) in patients with unilateral symptoms. The standard sequence (ULNT1-STD) and a distal-to-proximal sequence (ULNT1-DIST) were investigated. A local-initiated sequence may facilitate symptoms reproduction in CTS, and comparing the affected side with the unaffected side could improve the detection of altered median nerve mechanosensitivity when symptoms are not directly reproduced. Methods: A total of 134 consecutive patients with clinically suspected unilateral CTS were recruited. Nerve conduction studies were used as a reference test. Results: When considering only symptom reproduction as the criterion for a positive test, ULNT1-STD showed a sensitivity of 0.398 and a specificity of 0.780 (positive likelihood ratio [+LR]: 1.81; negative likelihood ratio [-LR]: 0.77); whereas ULNT1-DIST demonstrated a sensitivity of 0.548 with a specificity of 0.732 (+LR: 2.04; -LR: 0.62). When a positive test was defined by symptom reproduction or inter-limb asymmetry (in range of motion or sensory response), ULNT1-STD showed an improved sensitivity of 0.613 but a reduced specificity of 0.537 (+LR: 1.32; -LR: 0.72). In comparison, ULNT1-DIST increased its sensitivity to 0.871 with a specificity of 0.683 (+LR: 2.75; -LR: 0.19). Conclusions: ULNT1-DIST offers better diagnostic accuracy for CTS compared to the ULNT1-STD sequence, especially when interlimb asymmetries in range of motion or sensory response are considered. However, side-to-side comparisons have reduced utility in cases with bilateral symptoms, limiting their application in clinical practice.

The Additional Effect of Neurodynamic Slump and Suboccipital Muscle Inhibition to Passive Stretching of the Short Hamstring: A Single-Blind, Randomized Controlled Trial

BACKGROUND/OBJECTIVES

Hamstring shortening is a significant musculoskeletal condition affecting the posture and mobility of the spine and lower extremities. This study examined the impact of incorporating neurodynamic slump stretch and suboccipital muscle inhibition into passive static stretching on hamstring flexibility in individuals with short hamstrings.

METHODS

117 female participants were classified into three groups: the control group, which received passive static stretch of the hamstring muscle; the neurodynamic slump group, which received neurodynamic slump stretch with passive static stretch; and the suboccipital muscle inhibition group, which received suboccipital muscle inhibition with passive static stretch, for three sessions a week, 10 min each, for four weeks. The outcome measures were the popliteal angle test (PAT), straight leg raising (SLR) test, and forward bending test (FBT) at baseline, immediately following the first session and after four weeks.

RESULTS

Statistically significant differences were found within groups (p < 0.001) for all outcome measures. Between the groups, there was a more significant improvement in the PAT and the SLR tests, favoring the neurodynamic slump and suboccipital muscle inhibition groups in comparison with the passive static stretch group (p < 0.001) with no significant difference between the two groups after the first session and at four weeks of treatment. However, the FBT showed no significant differences immediately following the first session or at four weeks of treatment (p > 0.05).

CONCLUSIONS

This study found that incorporating neurodynamic slump stretch and suboccipital muscle inhibition into passive static stretch techniques effectively treats short hamstrings in healthy individuals.

Comparison of utilizing modified hold-relax, muscle energy technique, and instrument-assisted soft tissue mobilization on hamstring muscle length in healthy athletes: Randomized controlled trial

INTRODUCTION

The hamstring muscle shortness is the primary risk factor for sports-related injuries. Numerous treatments are available for lengthening of hamstring muscle. The main purpose of this study was to compare the immediate effect of modified hold-relax, muscle energy technique (MET), and instrument assisted soft tissue mobilization-Graston techniques (IASTM-GT) on length of hamstring muscle in young healthy athletes.

METHODS

60 athletes comprising of 29 females and 31 males were recruited in the present study. Participants were allocated to 3 groups of IASTM-GT (N = 20, 13 male, 7 female), Modified Hold-relax (N = 20, 8 male, 12 female), and MET (N = 20, 7 male, 13 female). Active knee extension and passive straight leg raising (SLR), and toe touch test were performed before and immediately after the intervention by a blinded assessor. For the comparison of dependent variables across time, 3*2 repeated measure ANOVA was utilized.

RESULTS

Interaction of group by time was significant for passive SLR (P < 0.001). Interaction of group by time was not significant for active knee extension (P = 0.17). The results showed that dependent variables increased significantly in all groups. The effect size (Cohen's d) in the groups of IASTM-GT, modified Hold-relax, and MET was 1.7, 3.17, and 3.12, respectively.

CONCLUSION

Although the measures were improved in all groups, it seems that IASTM-GT can be used as a safe and efficient treatment, which can be a suitable candidate alongside modified hold-relax and MET for increasing the hamstrings muscle length in healthy athletes.

Short-Term Effects of Three Types of Hamstring Stretching on Length, Neurodynamic Response, and Perceived Sense of Effort-A Randomised Cross-Over Trial

Background: Stretching techniques for hamstring muscles have been described both to increase muscle length and to evaluate nerve mechanosensitivity. Aim: We sought to evaluate the short-term effects of three types of hamstring stretching on hamstring length and report the type of response (neural or muscular) produced by ankle dorsiflexion and perceived sense of effort in asymptomatic subjects. Methods: A randomised cross-over clinical trial was conducted. A total of 35 subjects were recruited (15 women, 20 men; mean age 24.60 ± 6.49 years). Straight leg raises (SLR), passive knee extensions (PKE), and maximal hip flexion (MHF) were performed on dominant and non-dominant limbs. In addition, the intensity of the applied force, the type and location of the response to structural differentiation, and the perceived sensation of effort were assessed. Results: All stretching techniques increased hamstring length with no differences between limbs in the time*stretch interaction (p < 0.05). The perceived sensation of effort was similar between all types of stretching except MHF between limbs (p = 0.047). The type of response was mostly musculoskeletal for MHF and the area of more neural response was the posterior knee with SLR stretch. Conclusions: All stretching techniques increased hamstring length. The highest percentage of neural responses was observed in the SLR stretching, which produced a greater increase in overall flexibility.

Minimizing risk of iatrogenic nerve injury during peroneus longus tendon autograft harvest: a cadaveric study at different ankle or knee positions

PURPOSE

To evaluate the distances using ultrasound between the superficial peroneal nerve (SPN) and sural nerve along the peroneus longus tendon (PLT) autograft harvest path at different ankle or knee positions in order to minimize risk of iatrogenic nerve injury during PLT autograft harvest.

METHODS

Twenty-four fresh-frozen human cadaveric lower extremities were used to harvest a full-thickness PLT autograft with a tendon stripper. Four specimens were utilized to validate correct identification of nerves under ultrasound. Sonographically guided perineural injections were performed at the start point and end point of the PLT harvest path using coloured latex, followed by dissection with gross inspection. Using ultrasound, the distance from the peroneus brevis muscle to the sural nerve at different ankle positions (20° dorsiflexion, neutral, and 20° plantarflexion) was measured, and the distance from the end of the tendon stripper to the SPN at different knee positions (full extension and 90° flexion) was also measured. Measurements were performed by two separate observers using ImageJ software.

RESULTS

Cadaveric dissection showed the presence of latex around nerves in all four specimens. The average distance from the brevis muscle to the sural nerve increased significantly from dorsiflexion to plantarflexion. The shortest distance from the tenodesis site to the sural nerve was 5.8 ± 1.7 mm. There was no significant difference from the end of the tendon stripper to the SPN between full extension or 90° flexion of the knee.

CONCLUSION

When harvesting the PLT, it is recommended to place the ankle at plantarflexion. The knee at full extension or 90° flexion had no effect. Joint positions at the time of graft harvest should be monitored to reduce risks of iatrogenic nerve injury.

Reliability of the straight leg raise test for suspected lumbar radicular pain: A systematic review with meta-analysis

BACKGROUND

The passive straight leg raise (SLR) and crossed SLR are recommended tests for lumbar radicular pain. There are no recent reviews of test reliability.

OBJECTIVES

To summarize SLR and crossed SLR reliability in patients with suspected lumbar radicular pain.

DESIGN

Systematic review with meta-analysis.

METHOD

MEDLINE and CINAHL were searched for studies published before April 2021 that reported SLR or crossed SLR reliability in patients with low back-related leg pain. Supplemental analyses also included patients with low back pain only. Study selection, risk of bias assessment (QAREL), and data extraction were performed in duplicate. Kappa, intraclass correlation coefficients, and smallest detectable difference (SDD₉₅) quantified reliability. Meta-analysis was performed when appropriate. Confidence in the evidence was determined by applying GRADE principles.

RESULTS/FINDINGS

Fifteen studies met selection criteria. One-hundred-eighty-nine participants had low back-related leg pain. Four-hundred-thirty-nine were included in supplemental analyses. Meta-analyses showed at least fair inter-rater reliability when a positive SLR required provocation of lower extremity symptoms or pain. SLR reliability was at least moderate when testing included structural differentiation (e.g., ankle dorsiflexion). A low prevalence of positive crossed SLR tests led to wide-ranging reliability estimates. Confidence in the evidence for identifying a positive SLR or crossed SLR was moderate to very low. SDD₉₅ values for different raters measuring SLR range of motion ranged from 13 to 20°.

CONCLUSIONS

Reliability data support testing SLR with structural differentiation manoeuvres. Crossed SLR reliability data are inconclusive. Measurement error likely prohibits using SLR range of motion for clinical decision-making.