Margaret Roebuck

Matrix metalloproteinase expression is related to angiogenesis and histologic grade in spindle cell soft tissue neoplasms of the extremities.

We defined the immunocytochemical expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in benign soft tissue neoplasms, fibromatoses, and sarcomas, together with the activity of gelatinase MMPs and TIMPs measured by zymography and reverse zymography in a subset of cases. The most strongly expressed MMP in all tumors was MMP-1, with weaker expression of MMP-10, MMP-11, and MMP-14 in most tumors. Nuclear expression of MMP-1, MMP-8, and MMP-13 was an unusual feature. TIMP-2 was expressed in all tumors, with stronger expression in fibromatoses than in sarcomas. Fibromatoses and high-grade sarcomas showed greater MMP-1 expression than other groups, and endothelial MMP-2 expression was more extensive in sarcomas. Differences in MMP and TIMP expression might be linked to the biologic behavior of soft tissue neoplasms. The activation of endothelial MMP-2 linked to widespread MMP-14 expression provides a mechanism for sarcomas to modulate their matrix and facilitate angiogenesis.

Normal shoulder muscular activation and co-ordination during a shoulder elevation task based on activities of daily living: An electromyographic study

Studies of normal shoulder function have often failed to consider the inter‐relationship between different muscle groups in activities relevant to daily life. Upper limb functional status was assessed in 12 healthy male volunteers using the Functional Impairment Test‐Hand, Neck, Shoulder and Arm test (FIT‐HaNSA). Electromyography was then used to study the activity and coordination of 13 muscles (10 by surface electrodes, 3 by fine‐wire intramuscular electrodes) around the shoulder during a dynamic movement task based on the shelf‐lifting task in FIT‐HaNSA. Muscles were grouped for analysis into deltoid (anterior, middle, and posterior divisions), adductors (latissimus dorsi and teres major), rotator cuff (supraspinatus, infraspinatus, and subscapularis), and elbow flexor (brachioradialis, biceps brachii) groups. There were no significant inter‐session effects. Using cross‐correlation analysis to investigate the whole time‐course of activation, there were highly significant positive correlations (p < 0.001) between the deltoid and rotator cuff, the deltoid and adductor and the adductor and rotator cuff groups, and a significant negative correlation between the deltoid and elbow flexor groups (p = 0.031). We conclude that the deltoid, adductor, and rotator cuff muscles all contribute to the muscular component of glenohumeral joint stability. Muscular stability can be adapted as required to meet task‐specific demands.

Shoulder muscle activation and coordination in patients with a massive rotator cuff tear: an electromyographic study.

Adaptive muscle activation strategies following a massive rotator cuff tear (MRCT) are inadequately understood, and the relationship among muscles during everyday activities has not been considered. Thirteen healthy subjects comprised the control group, and 11 subjects with a MRCT the patient group. Upper limb function was assessed using the Functional Impairment test‐hand, neck, shoulder, and arm (FIT‐HaNSA). Electromyography (EMG) was recorded from 13 shoulder muscles, comprising five muscle groups, during a shelf‐lifting task. Mean FIT‐HaNSA scores were significantly lower in MRCT patients (p ≤ 0.001), reflecting a severe functional deficit. In MRCT patients, EMG signal amplitude was significantly higher for the biceps brachii‐brachioradialis (p < 0.001), upper trapezius‐serratus anterior (p = 0.025), muscle groups and for the latissimus dorsi (p = 0.010), and teres major (p = 0.007) muscles. No significant differences in the correlation among muscle groups were identified, pointing to an unchanged neuromuscular strategy following a tear. In MRCT patients, a reorganization of muscle activation strategy along the upper limb kinetic chain is aimed at reducing demand on the glenohumeral joint. Increased activation of the latissimus dorsi and teres major muscles is an attempt to compensate for the deficient rotator cuff. Re‐education towards an alternate neuromuscular control strategy appears necessary to restore function.

Electromyographic assessment of muscle fatigue in massive rotator cuff tear

Shoulder muscle fatigue has not been assessed in massive rotator cuff tear (MRCT). This study used EMG to measure fatigability of 13 shoulder muscles in 14 healthy controls and 11 patients with MRCT. A hand grip protocol was applied to minimise artifacts due to pain experience during measurement. The fatigue index (median frequency slope) was significantly non-zero (negative) for anterior, middle, and posterior parts of deltoid, supraspinatus and subscapularis muscles in the controls, and for anterior, middle, and posterior parts of deltoid, and pectoralis major in patients (p ≤ 0.001). Fatigue was significantly greater in patients compared to the controls for anterior and middle parts of deltoid and pectoralis major (p ≤ 0.001). A submaximal grip task provided a feasible way to assess shoulder muscle fatigue in MRCT patients, however with some limitations. The results suggest increased activation of deltoid is required to compensate for lost supraspinatus abduction torque. Increased pectoralis major fatigue in patients (adduction torque) likely reflected strategy to stabilise the humeral head against superior subluxing force of the deltoid. Considering physiotherapy as a primary or adjunct intervention for the management of MRCT, the findings of this study generate a base for future clinical studies aiming at the development of evidence-based protocols.

Subacromial impingement syndrome: An electromyographic study of shoulder girdle muscle fatigue

Muscle fatigue affecting glenohumeral and/or scapular muscles is suggested as one of the contributing factors to the development of subacromial impingement syndrome (SAIS). Nonetheless, the fatigability of shoulder girdle muscles in association with the pathomechanics of SAIS has not been reported. This study aimed to measure and compare fatigue progression within the shoulder girdle musculature of patients and healthy controls. 75 participants including 39 patients (20 females; 19 males) and 36 healthy controls (15 females; 21 males) participated in the study. Study evaluated the progression of muscle fatigue in 15 shoulder girdle muscles by means of surface and fine-wire EMG during submaximal contraction of four distinct movements (abduction, flexion, internal and external rotation). Shoulder strength, subjective pain experience (McGill Pain Questionnaire), and psychological status (Hospital Anxiety and Depression Scale) were also assessed. The results were compared between patient and control groups according to the gender. Despite marked fatigue observed in the majority of muscles particularly during flexion and abduction at 90°, overall results indicated a lower tendency of fatigue progression in the impingement group across the tests (p < 0.05 - p < 0.001). Shoulder Strength, pain experience, and psychological status were significantly different between the two groups (P < .05). Lower tendency to fatigue progression in the impingement group can be attributed to the presence of fear avoidance and pain-related muscle inhibition, which in turn lead to adaptations in motor programme to reduce muscle recruitment and activation. The significantly higher levels of pain experience and anxiety/depression in the impingement group further support this proposition.

Pain, Functional Disability, Psychological Status, and Health-Related Quality of Life in Patients with Subacromial Impingement Syndrome

Abstract Background: Subacromial Impingement Syndrome (SAIS) is the comments painful shoulder condition leading to considerable functional loss. Considering numerous existing conservative and surgical interventions for SAIS, the use of optimal patient-centred outcome measures is essential. Study assessed various generic and shoulder-specific outcome measures in patients and healthy controls to provide baseline data and facilitate the development of evidence-based interventions. Methods: A total of 75 participants including 39 patients and 36 healthy controls were evaluated and compared by a battery of validated outcome tools: McGill Pain Questionnaire, Oxford Shoulder Score, Constant Murley Score, The Disability of the Arm, Shoulder and Hand, Upper Limb Function Index, Functional Impairment Test-Hand and Neck/Shoulder/Arm, Hospital Anxiety and Depression Scale, Short-Form Health Survey, and shoulder muscle strength. Results: All selected measures showed significant differences in the pain experience, upper limb functional capacity, psychological status (anxiety and depression), and health-related quality of life between SAIS patients and healthy controls in both female and male participant groups (p < 0.05–p < 0.001). Conclusion: The use of an array of patient-centred upper limb regional/joint-specific pain and functional measures combined with psychological status and quality of life tools is recommended for the evidence-based assessment of intervention outcome in patients with SAIS.