Ankle EMD correlation between dominant and non-dominant leg before and after fatigue
Author(s):
Flevas D. (Greece)
,
Flevas D. (Greece)
Affiliations:
Pappas E.
,
Pappas E.
Affiliations:
Ristanis S.
,
Ristanis S.
Affiliations:
Giakas I.
,
Giakas I.
Affiliations:
Vekris M.
,
Vekris M.
Affiliations:
Georgoulis A.
Georgoulis A.
Affiliations:
ESSKA Academy. Flevas D. 05/09/18; 209212; P01-312 Topic: Sports Related Injuries
Dr. Dimitrios A. Flevas
Dr. Dimitrios A. Flevas
Login now to access Regular content available to all registered users.

You can access free regular educational content on the ESSKA Academy by registering as an 'ESSKA Academy User’ here

Access to Premium content is currently a membership benefit.

Click here to join ESSKA or renew your membership.
Abstract
Discussion Forum (0)
Rate & Comment (0)
Objectives: The most common ankle injury consists of an inversion sprain that affects the lateral ligaments of the ankle. Electromechanical delay (EMD) is the time interval from the stimulation of a muscle by the alpha motoneuron to the first detected movement this muscle produces at a given joint and represents the time required by the muscles to provide a protective response to an injury mechanism. It has been suggested that EMD is a measure of the true effectiveness of the muscles to provide mechanical response and protection under real-life situations[1]. EMD can be affected by several factors including the mechanical properties of the elastic components of the muscle, the size and length of the muscle, its fiber type composition, and the presence of fatigue. One way to assess the protective mechanisms to an ankle injury seems to be the assessment of the EMD of the peroneals. The objective of this study was to compare the EMD reaction of the peroneals of the dominant and non-dominant leg of 9 athletes.

Methods: 9 male volunteers with a mean age of 32.9 years (range: 27-39, SD: 3.85), median Tegner: 7 (range: 6-8, SD: 0.5) participated. They all were amateur athletes on a regional level. None of them had any history of ankle injury or surgery or fracture on either lower extremity. Also none of them had any neurological problems. EMD was measured on an isokinetic dynamometer using surface tele-electromyography. All subjects followed an isokinetic fatigue protocol until eversion torque fell below 50% of initial torque for three consecutive repetitions. Repeated ANOVA measurements were used for statistical analysis.

Results: No significant difference was noted between the dominant and non-dominant leg of the volunteers (p=0.946). Fatigue caused a significant increase on EMD (p=0.021)

Conclusions: No significant difference was noted between the dominant and non-dominant leg of the volunteers. This finding implies that in an uninjured athlete both ankles, of the dominant and the non-dominant leg, seem to be under the same protection of the reactive response of the peroneals and subsequently both ankles are equally exposed to an injury. A recent study by Keles et al. demonstrated that exercise training decreases peroneal muscle reaction time after a 6-week eccentric/concentric isokinetic training program in healthy subjects[2]. Combining these findings rehabilitation programs should focus retraining reaction time to prevent injuries equally to both legs, either dominant or not. Another finding was that fatigue caused a significant increase on EMD. This finding is consistent with the current literature[3] and emphasizes the importance of proper conditioning in the prevention of delayed peroneal response for both ankles, either dominant leg or not.

Keywords:
Ankle, EMD, Dominant Leg, Fatigue
Objectives: The most common ankle injury consists of an inversion sprain that affects the lateral ligaments of the ankle. Electromechanical delay (EMD) is the time interval from the stimulation of a muscle by the alpha motoneuron to the first detected movement this muscle produces at a given joint and represents the time required by the muscles to provide a protective response to an injury mechanism. It has been suggested that EMD is a measure of the true effectiveness of the muscles to provide mechanical response and protection under real-life situations[1]. EMD can be affected by several factors including the mechanical properties of the elastic components of the muscle, the size and length of the muscle, its fiber type composition, and the presence of fatigue. One way to assess the protective mechanisms to an ankle injury seems to be the assessment of the EMD of the peroneals. The objective of this study was to compare the EMD reaction of the peroneals of the dominant and non-dominant leg of 9 athletes.

Methods: 9 male volunteers with a mean age of 32.9 years (range: 27-39, SD: 3.85), median Tegner: 7 (range: 6-8, SD: 0.5) participated. They all were amateur athletes on a regional level. None of them had any history of ankle injury or surgery or fracture on either lower extremity. Also none of them had any neurological problems. EMD was measured on an isokinetic dynamometer using surface tele-electromyography. All subjects followed an isokinetic fatigue protocol until eversion torque fell below 50% of initial torque for three consecutive repetitions. Repeated ANOVA measurements were used for statistical analysis.

Results: No significant difference was noted between the dominant and non-dominant leg of the volunteers (p=0.946). Fatigue caused a significant increase on EMD (p=0.021)

Conclusions: No significant difference was noted between the dominant and non-dominant leg of the volunteers. This finding implies that in an uninjured athlete both ankles, of the dominant and the non-dominant leg, seem to be under the same protection of the reactive response of the peroneals and subsequently both ankles are equally exposed to an injury. A recent study by Keles et al. demonstrated that exercise training decreases peroneal muscle reaction time after a 6-week eccentric/concentric isokinetic training program in healthy subjects[2]. Combining these findings rehabilitation programs should focus retraining reaction time to prevent injuries equally to both legs, either dominant or not. Another finding was that fatigue caused a significant increase on EMD. This finding is consistent with the current literature[3] and emphasizes the importance of proper conditioning in the prevention of delayed peroneal response for both ankles, either dominant leg or not.

Keywords:
Ankle, EMD, Dominant Leg, Fatigue
Code of conduct/disclaimer available in General Terms & Conditions

By clicking “Accept Terms & all Cookies” or by continuing to browse, you agree to the storing of third-party cookies on your device to enhance your user experience and agree to the user terms and conditions of this learning management system (LMS).

Cookie Settings
Accept Terms & all Cookies