Stretching the evidence behind tennis elbow: mobile app user guide

Tennis elbow (TE), formally known as lateral epicondylalgia, is a musculoskeletal condition associated with pain over the lateral elbow and histological changes of the common extensor tendon. Numerous treatments are advocated for this condition, with recent developments in the use of mobile technology now added to the list

Isometric exercise above but not below an individual’s pain threshold influences pain perception in people With lateral epicondylalgia

OBJECTIVE: To examine the acute effects of isometric exercise of different intensities on pain perception in individuals with chronic lateral epicondylalgia. METHODS: Participants performed three experimental tasks completed in a randomised order on separate days: control (no exercise) and isometric wrist extension (10 x 15 sec) at load 20% below (infra-threshold) and 20% above (supra-threshold) an individual’s pain threshold. Self-reported pain intensity (11-point numeric rating scales (NRS)), pressure pain threshold and pain free grip were assessed by a blinded examiner before, immediately after and 30min after task performance. Correlation between pain ratings and clinical variables, including pain and disability and kinesiophobia was performed. RESULTS: 24 individuals with unilateral lateral epicondylalgia of median 3-month duration participated. Pain intensity during contraction was significantly higher during supra-threshold exercise than infra-threshold exercise (Mean difference in NRS 1.0, 95%CI 0.4, 1.5, p = 0.002). Pain intensity during supra-threshold exercise was significantly correlated with pain and disability (R=0.435; p=0.034) and kinesiophobia (R=0.556, p=0.005). Pain intensity was significantly higher immediately after performance of supra-threshold exercise, compared to infra-threshold exercise (p=0.01) and control (p<0.001) conditions, while infra-threshold exercise and control conditions were comparable. Thirty minutes later, pain levels remained significantly higher for supra-threshold exercise compared to infra-threshold exercise (p=0.043). Pressure pain threshold and pain free grip showed no significant effects of time, condition, or time by condition (p>0.05). DISCUSSION: Individuals with lateral epicondylalgia demonstrated increased pain intensity following an acute bout of isometric exercise performed at an intensity above, but not below, their individual pain threshold. Further investigation is needed to determine whether measurement of an individual’s exercise induced pain threshold may be important in reducing symptom flares associated with exercise

Unsupervised isometric exercise versus wait-and-see for lateral elbow tendinopathy

Purpose This study aimed to investigate the effect of unsupervised isometric exercise compared with a wait-and-see approach on pain, disability, global improvement, and pain-free grip strength in individuals with lateral elbow tendinopathy. Methods Forty participants with unilateral lateral elbow tendinopathy of at least 6 wk duration were randomized to either wait-and-see (n = 19) or a single supervised instruction session by a physiotherapist, followed by an 8-wk unsupervised daily program of progressive isometric exercise (n = 21). Primary outcomes were Patient-Rated Tennis Elbow Evaluation, global rating of change on a six-point scale (dichotomized to success and no success) and pain-free grip strength at 8 wk. Secondary outcomes were resting and worst pain on an 11-point numerical rating scale, and thermal and pressure pain thresholds as a measure of pain sensitivity. Results Thirty-nine (98%) participants completed 8-wk measurements. The exercise group had lower Patient-Rated Tennis Elbow Evaluation scores compared with wait-and-see at 8 wk (standardized mean difference [SMD],-0.92; 95% confidence interval [CI],-1.58 to-0.26). No group differences were found for success on global rating of change (29% exercise vs 26% wait-and-see (risk difference, 2.3%; 95% CI,-24.5 to 29.1)), or pain-free grip strength (SMD,-0.33; 95% CI,-0.97 to 0.30). No differences were observed for all secondary outcomes except for worst pain, which was moderately lower in the exercise group (SMD,-0.80; 95% CI,-1.45 to-0.14). Conclusions Unsupervised isometric exercise was effective in improving pain and disability, but not perceived rating of change and pain-free grip strength when compared with wait-and-see at 8 wk. With only one of the three primary outcomes being significantly different after isometric exercises, it is doubtful if this form of exercise is efficacious as a sole treatment. © Lippincott Williams & Wilkins

Shear-wave velocity of the patellar tendon and quadriceps muscle is increased immediately after maximal eccentric exercise

Purpose: To determine whether stiffness of the patellar tendon and quadriceps muscles is altered immediately after and 48 h after a single bout of maximal eccentric exercise of the knee extensor muscles. Methods: Thirteen healthy individuals [group mean (SD) age 22.4 (3.5) years; 7 female] performed a single bout of maximal eccentric exercise of the non-dominant knee extensors, using an isokinetic dynamometer. Shear-wave velocity (an index of tissue stiffness) was recorded from the patellar tendon, vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL), before, following (post0), and 48 h after (post48) exercise. To investigate features of exercise induced muscle damage, maximal voluntary isometric contraction (MVIC) and self-reported pain and stiffness (numerical rating scales 0 = no pain/stiffness to 100 = worst imaginable pain/stiffness) were measured before, post0, and post48 exercise. Serum creatine kinase (CK) was measured before and post48 exercise. Results: Compared to preexercise, MVIC decreased and self-reported pain and stiffness increased at post0 and post48 and CK levels increased at post48 (all p < 0.01). Compared to preexercise, shear-wave velocity was greater at post0 for the patellar tendon [15.9 (24.6)%, p = 0.01] and RF [23.6 (16.7)%, p < 0.001], each returning to baseline by post48. No significant differences were observed for VL or VM post0 or post48 exercise. Conclusion: Maximal eccentric exercise produced an immediate increase in the stiffness of the patellar tendon and RF, resolving by 48 h. As this change was not observed in VL and VM, future studies may explore heterogeneity within synergist muscles following eccentric exercise. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature

Response to considerations on “Achilles tendinopathy and patellar tendinopathy display opposite changes in elastic properties”

Letter to the edito

Achilles and patellar tendinopathy display opposite changes in elastic properties: A shear wave elastography study

To compare tendon elastic and structural properties of healthy individuals with those with Achilles or patellar tendinopathy. Sixty-seven participants (22 Achilles tendinopathy, 17 patellar tendinopathy, and 28 healthy controls) were recruited between March 2015 and March 2016. Shear wave velocity (SWV), an index of tissue elastic modulus, and tendon thickness were measured bilaterally at mid-tendon and insertional regions of Achilles and patellar tendons by an examiner blinded to group. Analysis of covariance, adjusted for age, body mass index, and sex was used to compare differences in tendon thickness and SWV between the two tendinopathy groups (relative to controls) and regions. Tendon thickness was included as a covariate for analysis of SWV. Compared to controls, participants with Achilles tendinopathy had lower SWV at the distal insertion (Mean difference MD; 95% CI: −1.56; −2.49 to −0.62 m/s; P <.001) and greater thickness at the mid-tendon (MD 0.19; 0.05-0.33 cm; P =.007). Compared to controls, participants with patellar tendinopathy had higher SWV at both regions (MD 1.25; 0.40-2.10 m/s; P =.005) and greater thickness proximally (MD 0.17; 0.06-0.29 cm; P =.003). Compared to controls, participants with Achilles and patellar tendinopathy displayed lower Achilles tendon elastic modulus and higher patellar tendon elastic modulus, respectively. More research is needed to explore whether maturation, aging, or chronic load underlie these findings and whether current management programs for Achilles and patellar tendinopathy need to be tailored to the tendon. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Lt

Patellar and Achilles tendinopathies are predominantly peripheral pain states: A blinded case control study of somatosensory and psychological profiles

study design Case–control design. background Tendinopathy is characterised by pain on tendon loading. In persistent cases of upper limb tendinopathy, it is frequently associated with central nervous system sensitisation, whereas less commonly linked in the case of persistent lower limb tendinopathies. Objectives Compare somatosensory and psychological profiles of participants with persistent patellar (PT) and Achilles tendinopathies (AT) with pain free controls. Methods A comprehensive battery of Quantitative Sensory Testing (QST) was assessed at standardised sites of the affected tendon and remotely (lateral elbow) by a blinded assessor. Participants completed the Victorian Institute of Sports Assessment, a health-related quality of life questionnaire, the Hospital Anxiety and Depression Scale and the Active Australia Questionnaire. Independent t-test and analysis of covariance (sex-adjusted and age-adjusted) were performed to compare groups. results Participants with PT and AT did not exhibit differences from controls for the QST at the remote site, but there were differences at the affected tendon site. Compared with controls, participants with PT displayed significantly lower pressure pain threshold locally at the tendon (p=0.012) and fewer single limb decline squats before pain onset, whereas participants with AT only displayed fewer single heel raises before pain onset, but this pain was of a higher intensity. Conclusion PT and AT appear to be predominantly local not widespread pain states related to loading of tendons without significant features of central sensitisation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved