Bilateral Kinematic Indicators Of The Specific Hip And Knee Postural Adaptation Of Handball Players

Purpose: Considering the everyday training, handball players promote specific postural adaptation. Determining of postural and functional unilateral sports inherent asymmetry could improve the performance and provide injury prevention. The aim of this study was to examine whether there were significant differences in hip and knee range of motion (ROM), in all planes, between stance and kicking leg of handball players.Methods: Research was conducted in the Laboratory for biomechanics of the Institute of Kinesiology at the Faculty of Kinesiology, University of Zagreb, during May 2016. Assessment was performed in 2 stages, on a randomized sample comprised of 25 male subjects, age ranging from 19 to 24 years with a mean 21.8. Participants were recruited from the population of students who train handball 10.44 +/- 3 years. Based on the short version of the International Physical Activity Questionnaire (IPAQ), a high level of physical activity of the participants was determined. Kinematic measurements were performed through the Modified Thomas Test (MTT), which is standard for sagittal evaluation of the passive hip extension and knee flexion, giving the information on the flexibility of monoarticular and biarticular hip flexors, whose segmental postural adaptation can generate end movements in other planes. Therefore, the sample of variables were 4 angles: knee flexion and hip extension, rotation and abduction, all bilaterally. The research was performed using automatized optoelectronic kinematic measurement system ELITE 2002 (BTS Bioengineering Corp., Milano) with 8 cameras, frequency 100 Hz and 9 passive markers placed at bony prominences. Data processing was done using the Smart Analyzer software package. Since distribution showed normality, the t-test for independent samples was used. Calculations were performed using Statistica 12 software package.Results: Kicking leg was more mobile in the hip, through the extension ROM (2.36 degrees, p=0.18), and especially in the frontal plane where significantly higher abduction angle was found (2.55 degrees, p=0.03). Knee ROM was greater for the stance leg, although no significance was found (1.56 degrees, p=0.45). Posture in the horizontal plane was neutral for both legs.Conclusions: Handball players are characterized by greater mobility of the kicking leg in the hip. With the exception of hip abduction, this study has not found that multi-year handball training forms a postural adaptation of the lower extremities with significant bilateral asymmetries. Bilateral kinematic indicators determined in this study could contribute to a better understanding of the role of segmental hip and knee movements in posture, postural adaptation and locomotion of handball players, and provide guidelines for the prevention and rehabilitation of neuromuscular deficits and their consequences.