Effects of eccentric overload training on patellar tendon and vastus lateralis in three days of consecutive running.
BACKGROUND
The analysis of structural changes in patellar tendon and muscle of healthy subjects in response to mechanical loads provides useful insight into the mechanism underlying overuse injuries.


METHODS
Changes produced in tendon and muscles structures after eccentric overload training and three consecutive running days were examined. Twenty healthy subjects were recruited and divided into two groups. One group (ECC) performed eccentric overload squat training (six weeks). After such training, the ECC group performed three running sessions on consecutive days, as did the control group (CONT). The structure of their patellar tendons and vastus lateralis muscles was quantified using ultrasound and Doppler imaging. Images were obtained before and after eccentric training for the ECC group and on every day of running performance for both groups.


RESULTS
After eccentric training, the ECC group experienced an increase in cross-sectional area (CSA) of patellar tendon (P=0.012). After every day of running, the ECC group experienced a decrease in CSA (P=0.027). In the CONT group, after one day of running a significant increase was observed in anteroposterior width of their patellar tendon (P=0.028), as well as a decrease in pennation angle of vastus lateralis muscle (P=0.028) within three days of running sessions.


CONCLUSIONS
Eccentric overload training brought about changes in the patellar tendon consistent with an improvement in the quality of the tissue. The ECC group in our study showed a more normalised pattern than the CONT group in the running performance, in agreement with previous research.


METHODS
Level 3, controlled trial.
ValorA Research Group, Health Sciences Faculty, Universidad San Jorge, Zaragoza, Spain. Electronic address: fsanz79@yahoo.es.
Fernando
F
Sanz-López
ValorA Research Group, Health Sciences Faculty, Universidad San Jorge, Zaragoza, Spain.
César
C
Berzosa
Department of Health Sciences, Faculty of Health Sciences, University of Jaén, Jaén, Spain; Research Group CTS-026: Study Group on Physical Activity, Physiotherapy and Health, Jaén, Spain.
Fidel
F
Hita-Contreras
Department of Health Sciences, Faculty of Health Sciences, University of Jaén, Jaén, Spain; Research Group CTS-026: Study Group on Physical Activity, Physiotherapy and Health, Jaén, Spain.
Antonio
A
Martínez-Amat
D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D017847:Patellar Ligament / Q000000981:diagnostic imaging* / Q000502:physiology; D064797:Physical Conditioning, Human / Q000379:methods*; D052097:Quadriceps Muscle / Q000000981:diagnostic imaging* / Q000502:physiology; D012420:Running / Q000502:physiology*; D014463:Ultrasonography; D055815:Young Adult
Doppler; Muscle; Pennation angle; Tendon tissue; Ultrasound