Neuromuscular control and exercise-related leg pain in triathletes.
Previous studies have shown that cycling can directly influence neuromuscular control during subsequent running in some highly trained triathletes. A relationship between this altered neuromuscular control of running and musculoskeletal pain and injury has been proposed; however, this link has not been investigated.


OBJECTIVE
This study aimed to evaluate the influence of cycling on neuromuscular control during subsequent running in highly trained triathletes with and without exercise-related leg pain (ERLP).


METHODS
Participants were 34 highly trained triathletes: 10 triathletes with a history of ERLP and 24 training-matched control triathletes with no history of ERLP. Knee and ankle kinematics and leg muscle recruitment were compared between a baseline run (no prior exercise) and a transition run (preceded by cycling; i.e., run vs cycle run).


RESULTS
Knee and ankle joint kinematics were not different between baseline and transition runs for any triathletes: absolute mean difference (+/-95% confidence interval) was 1.49 degrees +/- 0.17 degrees. However, muscle recruitment was different between baseline and transition runs, defined by absolute mean difference in EMG amplitude > or = 10%, in 5 of 24 control triathletes (11/130 muscles exhibited altered recruitment) and in 5 of 10 triathletes with a history of ERLP (12/50 muscles exhibited altered recruitment). This represents a relative risk of 2.40 (0.89-6.50; P = 0.089) when defined by athletes and 2.62 (1.34-6.01; P < 0.01) when defined by muscles. The magnitude of change in muscle recruitment between baseline and transition runs was not different between control (14.10% +/- 2.34%) and ERLP triathletes (16.31% +/- 3.64%; P = 0.41).


CONCLUSIONS
This study demonstrates an association between ERLP in triathletes and their neuromuscular control when running off the bike.
Chapman
Andrew R
AR
Division of Physiotherapy, The University of Queensland, Brisbane, Australia. archapman@mac.com
Hodges
Paul W
PW
Briggs
Andrew M
AM
Stapley
Paul J
PJ
Vicenzino
Bill
B
D000328:Adult; D001265:Athletic Injuries / Q000209:etiology* / Q000503:physiopathology; D020958:Australian Capital Territory; D001642:Bicycling / Q000502:physiology; D001696:Biomechanical Phenomena; D004576:Electromyography; D005260:Female; D006801:Humans; D007866:Leg / Q000503:physiopathology*; D008297:Male; D010146:Pain / Q000209:etiology* / Q000503:physiopathology; D010807:Physical Endurance / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012420:Running / Q000502:physiology