Upper limb muscle imbalance in tennis elbow: A functional and electromyographic assessment

Abstract

The purpose of this study was to investigate strength, fatigability, and activity of upper limb musculature to elucidate the role of muscular imbalance in the pathophysiology of tennis elbow. Sixteen patients clinically diagnosed with tennis elbow, recruited from a university hospital upper limb orthopedic clinic, were compared with 16 control subjects with no history of upper limb musculoskeletal problem, recruited from university students and staff. Muscle strength was measured for grip, metacarpophalangeal, wrist, and shoulder on both sides. Electromyographic activity (RMS amplitude) and fatigue characteristics (median frequency slope) of five forearm and two shoulder muscles were measured during isometric contraction at 50% maximum voluntary contraction. All strength measurements showed dominance difference in C, but none in TE. In tennis elbow compared to controls, hand/wrist and shoulder strength and extensor carpi radialis (ECR) activity were reduced ( p < 0.05), while fatigue was normal. A global upper limb weakness exists in tennis elbow. This may be due to disuse and deconditioning syndrome caused by fear avoidance, and needs to be addressed in prevention and treatment. Activation imbalance among forearm muscles (reduced extensor carpi radialis activity) in tennis elbow, probably due to protective pain-related inhibition, could lead to a widespread upper limb muscle imbalance. ß

Assessment of the risk and biomechanical consequences of lateral epicondylalgia by estimating wrist and finger muscle capacities in tennis players

“…Our findings partially contradicted those of Alizadehkhaiyat et al (2007Alizadehkhaiyat et al ( , 2009. These authors noted an overall weakness of wrist flexion and an increase in ECRB muscle activation in Recovered players.…”

“…Another explanation is that the measurement approach used by these authors differed substantially from the one used in this study. Alizadehkhaiyat et al (2007Alizadehkhaiyat et al ( , 2009) directly estimated muscle force capacities and ratios using the measured net wrist moments. However, as already explained in the introduction, net joint moments are not representative of muscle force capacities since these measurements corresponded to the resultant action of all the muscles involved, including both synergistic and antagonistic actions.…”

“…Assessing the relative force-generating capacity between extensor and flexor muscles, referred to as 'muscle capacity ratio' in this article, therefore appears pertinent in investigating lateral epicondylalgia risks and muscular adaptations resulting from playing tennis. Previous assessments of upper limb muscle capacity ratio were based only on maximum isometric net joint moments (Alizadehkhaiyat, Fisher, Kemp, Vishwanathan, & Frostick, 2007Coombes et al, 2012) or EMG activity (Bazzucchi, Riccio, & Felici, 2008). However, these previous studies suffered from several limitations in their assessment of muscle capacity.…”

Fadiga dos músculos extensores do punho diminui a força de preensão palmar

“…Studies sought to evaluate the function of the forearm muscles in professional tennis players with or without epicondylitis; among the findings, the authors report the need to evaluate activation and fatigue in wrist extensor muscle in an attempt to identify players more susceptible to development of lateral epicondylitis 18,37 . This study sought to identify the relation of fatigue of the extensors in the changes of grip strength and lateral pinch in normal individuals, since the findings regarding grip indicate the need for future studies analyzing the pattern in individuals with elbow lateral epicondylitis, commonly observed in the population assisted by physical therapy.…”

“…Tang et al 17 describe that changes in biomechanical parameters of the wrist can be an important cause of diseases and dysfunctions. Alizadehkhaiyat et al 18 describe the fatigue as a possible etiology of wrist and elbow dysfunctions.…”