Manickaraj, N and Bisset, LM and Ryan, M and Kavanagh, JJ, Muscle activity during rapid wrist extension in people with lateral epicondylalgia, Medicine and Science in Sports and Exercise, 48, (4) pp. 599-606. ISSN 0195-9131 (2016) [Refereed Article]
Copyright © 2016 by the American College of Sports Medicine.
Background: Individuals with lateral epicondylalgia (LE) have delayed upper limb reaction time (RT); however, it is unknown if the mechanisms of this dysfunction are related to neural processing or the affected forearm muscles. The aim of this study was to examine the timing of processes that occur before and after forearm muscles are activated during the RT task.
Methods: Eleven LE (42 ± 11 yr) and 11 healthy controls (42 ± 11 yr) performed rapid wrist extension in response to an audio cue. Intramuscular EMG was obtained from extensor carpi radialis brevis (ECRB), extensor digitorum communis (EDC), extensor carpi ulnaris (ECU), and anconeus. Premotor time (PMT) was the duration from an audio cue to the onset of muscle activity, and motor time (MT) was the onset of muscle activity to the onset of wrist extension. Standard clinical assessments of LE were also performed.
Results: RT was significantly slower (33; 95% CI, 1-66 ms) in the LE group. There were no group differences in PMT and the order of muscle activation. Instead, the MT of ECRB (18; 95% CI, 6-31 ms), EDC (12; 95% CI, 1-23 ms), ECU (28; 95% CI, 9-46 ms), and anconeus (33; 95% CI, 11-56 ms) showed significant delay in LE group. Regression analyses revealed that the duration of LE could predict RT, ECRB, and anconeus PMT, whereas cold pain threshold predicted ECRB MT.
Conclusions: Delayed RT in LE was predominantly caused by deficits in ECRB and EDC MT. This study provides preliminary evidence that in the people with longer LE symptoms, duration appeared to have faster RT, although confirmation of this finding is required before firm conclusions can be drawn.
|Item Type:||Refereed Article|
|Keywords:||pain, motor control, tennis elbow, reaction time|
|Research Division:||Health Sciences|
|Research Group:||Sports science and exercise|
|Research Field:||Motor control|
|Objective Group:||Clinical health|
|Objective Field:||Diagnosis of human diseases and conditions|
|UTAS Author:||Manickaraj, N (Dr Nagarajan Manickaraj)|
|Web of Science® Times Cited:||3|
|Deposited By:||Health Sciences|
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