Muscle Activity during Rapid Wrist Extension in People with Lateral Epicondylalgia
Author(s)
Manickaraj, Nagarajan
Bisset, Leanne M
Ryan, Michael
Kavanagh, Justin J
Year published
2016
Metadata
Show full item recordAbstract
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 T 11 yr) and 11 healthy controls (42 T 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 ...
View more >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 T 11 yr) and 11 healthy controls (42 T 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.
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View more >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 T 11 yr) and 11 healthy controls (42 T 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.
View less >
Journal Title
Medicine and Science in Sports and Exercise
Volume
48
Issue
4
Subject
Sports science and exercise
Sports science and exercise not elsewhere classified
Medical physiology
Health services and systems
Public health
Clinical sciences