Is there an association between metabolic syndrome and rotator cuff related shoulder pain? A systematic review”.

Objectives Rotator cuff-related shoulder pain (RCRSP) is a common upper limb complaint. It has been suggested that this condition is more common among people with cardiometabolic risk factors. This systematic review has synthesised evidence from case–control, cross-sectional and cohort studies on the association between metabolic syndrome (MetS) and RCRSP. Design and data sources Five medical databases (MEDLINE, EMBASE, SCOPUS, CINAHL and AMED) and reference checking methods were used to identify all relevant English articles that considered MetS and RCRSP. Studies were appraised using the Newcastle-Ottawa Scale (NOS). Two reviewers performed critical appraisal and data extraction. Narrative synthesis was performed via content analysis of statistically significant associations. Results Three cross-sectional, two case–control and one cohort study met the inclusion criteria, providing a total of 1187 individuals with RCRSP. Heterogeneity in methodology and RCRSP or MetS definition precluded a meaningful meta-analysis. Four of the included studies identified associations between the prevalence of MetS and RCRSP. Studies consistently identified independent cardiometabolic risk factors associated with RCRSP. All studies were level III evidence. Summary and conclusion The low-moderate quality evidence included in this review suggests an association between MetS and RCRSP. Most studies demonstrated moderate quality on appraisal. The direction of association and cardiometabolic factors influencing should be investigated by longitudinal and treatment studies. These preliminary conclusions and clinical utility should be treated with caution due to limitations of the evidence base.Peer reviewedFinal Published versio

Does type 1 diabetes mellitus affect Achilles tendon response to a 10 km run? A case control study Epidemiology of musculoskeletal disorders

Background: Achilles tendon structure deteriorates 2-days after maximal loading in elite athletes. The load-response behaviour of tendons may be altered in type 1 diabetes mellitus (T1DM) as hyperglycaemia accelerates collagen cross-linking. This study compared Achilles tendon load-response in participants with T1DM and controls. Methods: Achilles tendon structure was quantified at day-0, day-2 and day-4 after a 10 km run. Ultrasound tissue characterisation (UTC) measures tendon structural integrity by classifying pixels as echo-type I, II, III or IV. Echo-type I has the most aligned collagen fibrils and IV has the least. Results: Participants were 7 individuals with T1DM and 10 controls. All regularly ran distances greater than 5 km and VISA-A scores indicated good tendon function (T1DM = 94 +/- 11, control = 94 +/- 10). There were no diabetic complications and HbA1c was 8.7 +/- 2.6 mmol/mol for T1DM and 5.3 +/- 0.4 mmol/mol for control groups. Baseline tendon structure was similar in T1DM and control groups -UTC echo-types (I-IV) and anterior-posterior thickness were all p > 0.05. No response to load was seen in either T1DM or control group over the 4-days post exercise. Conclusion: Active individuals with T1DM do not have a heightened Achilles tendon response to load, which suggests no increased risk of tendon injury. We cannot extrapolate these findings to sedentary individuals with T1DM

Serum levels of oxylipins in achilles tendinopathy: An exploratory study

Background: Linoleic acid-derived oxidation products are found in experimental pain models. However, little is known about the levels of such oxylipins in human pain. In consequence, in the present study, we have undertaken a lipidomic profiling of oxylipins in blood serum from patients with Achilles tendinopathy and controls. Methodology/Principal findings: A total of 34 oxylipins were analysed in the serum samples. At a significance level of P<0.00147 (<0.05/34), two linoleic acid-derived oxylipins, 13-hydroxy-10E,12Z-octadecadienoic (13-HODE) and 12(13)-dihydroxy-9Z-octadecenoic acid (12,13-DiHOME) were present at significantly higher levels in the Achilles tendinopathy samples. This difference remained significant when the dataset was controlled for age, gender and body-mass index. In contrast, 0/21 of the arachidonic acid- and 0/4 of the dihomo-γ-linolenic acid, eicosapentaenoic acid or docosahenaenoic acid-derived oxylipins were higher in the patient samples at this level of significance. The area under the Receiver-Operator Characteristic (ROC) curve for 12,13-DiHOME was 0.91 (P<0.0001). Levels of four N-acylethanolamines were also analysed and found not to be significantly different between the controls and the patients at the level of P<0.0125 (<0.05/4). Conclusions/Significance: It is concluded from this exploratory study that abnormal levels of linoleic acid-derived oxylipins are seen in blood serum from patients with Achilles tendinopathy. Given the ability of two of these, 9- and 13-HODE to activate transient receptor potential vanilloid 1, it is possible that these changes may contribute to the symptoms seen in Achilles tendinopathy

Tendon neuroplastic training: changing the way we think about tendon rehabilitation: a narrative review

Tendinopathy can be resistant to treatment and often recurs, implying that current treatment approaches are suboptimal. Rehabilitation programmes that have been successful in terms of pain reduction and return to sport outcomes usually include strength training. Muscle activation can induce analgesia, improving self-efficacy associated with reducing one's own pain. Furthermore, strength training is beneficial for tendon matrix structure, muscle properties and limb biomechanics. However, current tendon rehabilitation may not adequately address the corticospinal control of the muscle, which may result in altered control of muscle recruitment and the consequent tendon load, and this may contribute to recalcitrance or symptom recurrence. Outcomes of interest include the effect of strength training on tendon pain, corticospinal excitability and short interval cortical inhibition. The aims of this concept paper are to: (1) review what is known about changes to the primary motor cortex and motor control in tendinopathy, (2) identify the parameters shown to induce neuroplasticity in strength training and (3) align these principles with tendon rehabilitation loading protocols to introduce a combination approach termed as tendon neuroplastic training. Strength training is a powerful modulator of the central nervous system. In particular, corticospinal inputs are essential for motor unit recruitment and activation; however, specific strength training parameters are important for neuroplasticity. Strength training that is externally paced and akin to a skilled movement task has been shown to not only reduce tendon pain, but modulate excitatory and inhibitory control of the muscle and therefore, potentially tendon load. An improved understanding of the methods that maximise the opportunity for neuroplasticity may be an important progression in how we prescribe exercise-based rehabilitation in tendinopathy for pain modulation and potentially restoration of the corticospinal control of the muscle-tendon complex

The VISA-A (sedentary) should be used for sedentary patients with Achilles tendinopathy: a modified version of the VISA-A developed and evaluated in accordance with the COSMIN checklist

ObjectiveTo develop and evaluate a modified version of the Victorian Institute of Sport Assessment-Achilles (VISA-A) questionnaire, for use in sedentary patients with Achilles tendinopathy, using the Consensus-based Standards for the selection of health Measurement Instruments recommendations.MethodsTwenty-two sedentary patients with Achilles tendinopathy completed the VISA-A and provided feedback regarding the relevance, comprehensiveness and comprehensibility of each item, response options and instructions. Patient and professional feedback was used to develop the VISA-A (sedentary) questionnaire. Reliability, validity and responsiveness of the VISA-A (sedentary) was evaluated in 51 sedentary patients with Achilles tendinopathy: 47.1% women, mean age 64.8 (SD 11.24).ResultsFactor analysis identified two dimensions (symptoms and activity) for the VISA-A (sedentary). Test-retest reliability was excellent for symptoms (intraclass correlation coefficient, ICC=0.991) and activity (ICC=0.999). Repeatability was 1.647 for symptoms and 0.549 for activity. There was a significant difference between the VISA-A and VISA-A (sedentary) scores both pretreatment and post-treatment. There was stronger correlation between the pretreatment to post-treatment change in the VISA-A (sedentary) scores (r=0.420 for symptoms, r=0.407 for activity) and the global rating of change than the VISA-A scores (r=0.253 for symptoms, r=0.186 for activity).ConclusionThe VISA-A (sedentary) demonstrates adequate reliability, validity and responsiveness in sedentary patients with Achilles tendinopathy. The VISA-A (sedentary) is a more appropriate measure than the VISA-A for this cohort and is recommended for clinical and research purposes