european college of sport science

PP-BM03 Biomechanics 3
rotation velocity of the shank segment was significantly lower during the start phase than during the middle phase. Therefore, the leg
swing velocity during the start phase can be obtained mainly due to the increment of the forward rotation velocity of the thigh segment.
The previous study had reported that the knee joint during the foot contact phase should not be extended to transfer the hip extension
velocity effectively to the leg swing velocity during the middle phase (Ito et al., 1998). During the start phase, however, the extension velocity
of the knee joint and the amplitudes of the knee joint changes were greater in the start phase than in the middle phase. In addition,
the angle of the shank segment was smaller as compared to that during the middle phase. It is likely that the elite sprinters could obtain
the leg swing velocity by the knee extension due to the forward rotation of the thigh segment during the start phase.
References:
ITO.A et al (1998) Relationship between sprint running movement and velocity at full speed phase during a 100 m race. Japan Journal of
Physical Education 43, 260-273 (in Japanese).
THE RELATION ANALYSIS ON THROWING ANGLE AND MOTION IN JAVELIN THROW
TAZUKE, S.
DOSHISHA UNIVERSITY
Introduction: Throwing angle is important for better performance in track & field javelin throw. Javelin throwers tend to throw higher than
optimal angle. Coach instructs athlete to throw lower, and thrower tries to throw the javelin lower. However, it is difficult for throwers to
throw the javelin in lower angle. In this study the factors of the throwing angle in javelin throw were examined from the viewpoint of the
throwing motions.
Methods: Subjects were 9 javelin throwers (aged 19.33 years+-1.414, best performance 55.75m+-8.047, career of javelin throw
48.22month+-1.563, body height 171.04cm+-8.042, body weight 68.39kg+-10.925), 2 female and 7 male throwers. The experiment was
carried out from the throwing gate, which enables measuring the throwing angle, initial velocity and attack angle immediately, right after
throwing. Subjects got their throwing angle after throwing from this gate. For the first throw, they threw the javelin normally. From the
second to sixth throw, they were to declare their target throwing-angle beforehand, e.g. “higher” or “lower”, those were recorded. Every
throwing motion was filmed with two high-speed video cameras, film rate 250 / sec. by NAC. 21 out of 54 feasible throwing motions
were analyzed by the three-dimensional analysis with motion analysis software, Dynas-3D by Shin-Osaka Shokai Co., Ltd. The correlation
of the analyzed data, initial velocity of javelin (IVJ), velocity of body gravity (VBG), throwing angle (THA), attack angle (ATA), trunk angle
(TRA), arm angle (ARA), arm-trunk angle (A-TA) and elbow angle (EA) etc. at release (R); last (LFC), second (SFC) and third foot contact (TFC)
before releasing; third foot takeoff (TFT) before releasing were analyzed with the statistic software, SPSS.
Results and Discussion: A clear interactive relation was observed throwing angle and IVJ (r=-0.787, p=.01), VBG at R (r=-0.666, p=.01),
THA on the XZ plane at TFT (r=-0.711, p=.01) and at TFC (r=-0.882, p=.01), TRA on the XY plane at TFC (r=0.642, p=.05), TRA on the XZ plane
at R (r=0.593, p=.05) and SFC (r=0.700, p=.01), ARA on the XY plane at R (r=0.585, p=.05), and ARA on the XZ plane at SFC (r=0.552,
p=.05), at TFT (r=0.803, p=.01) and at TFC (r=0.724, p=.01), and left ARA on the XY plane at R (-0.597, p=.05), at LFC (r=-0.787, p=.01) and at
SFC (r=0.795, p=.01), left ARA on the XZ plane at RFC (r=0.550, p=.05) and at TFT (r=0.623, p=.05), A-TA at LFC (r=0.754, p=.01), TRA on the
ZY plane at R (r=0.700, p=.01) and at TFT (r=0.561, p=.05).
3 followings were mainly suggested from the experiment. 1) When the direction of javelin leans toward X axis at TFC, the throwing angle
is lower. 2) When the trunk leans toward horizontal line at TFC, the throwing angle is higher. 3) When the throwing arm leans toward
horizontal line at R, the throwing angle is higher.
Reference
1) Paavo V. Komi et al., Biomechanical Analysis of Olympic Javelin Throwers, INTERNATIONAL JOURNAL OF SPORT BIOMECHANICS, Vol.1,
Nr. 2, pp 139-150, 1985
BIOMECHANICAL ANALYSIS OF SPRINT RUNNING MOVEMENT OF ELITE SPRINTERS: THE THIGH AND SHANK SEG-
MENT’S MOVEMENT DURING THE CONTACT PHASE
FUKUDA, K., KIJIMA, K., ITO, A.
OSAKA UNIVERSITY OF HEALTH AND SPORT SCIENCES
Purpose:
The purpose of the present study was to examine the characteristics of lower limb’s movements around the top sprint speed phase of
elite sprinters. Especially, it focused on the movements of the thigh and shank segments during the contact phase.
Methods:
The subjects were 6 male (9.85-11.24 sec) and 6 female (10.99-13.10 sec) sprinters, who participated in a 100-m races in 11th IAAF World
Championships in Athletics, Osaka, Japan. Their running movements of one stride at approximately 60-m point were recorded by two
high-speed video cameras (200fps) and calculated the following parameters with three-dimensional direct linear transformation method:
average running velocity during the one stride, step length and step frequency as well as the average segment and joint angles of legs
during the contact phase. The contact phase was divided into the ratio of 43% and 57% as the deceleration and acceleration phases,
respectively. These phases were defined by the previous study (Fukuda et al., 2004) which calculated from the horizontal components of
the ground reaction forces.
Results and Discussion:
The average angular velocity of the shank segment during the deceleration and acceleration phases were positively related to their
running velocity. In these subjects, the average angular velocity of the shank during the deceleration phase was slightly higher than that
of the thigh. It is likely that the greater forward rotation velocity of the shank segment could be occurred by the deceleration force of the
initial impact. Consequently, the angular velocity of the knee joint showed a flexor direction during the deceleration phase. During the
acceleration phase, on the other hand, the average angular velocity of the thigh segment increased, especially for the lower sprint velocity
group, and did not showed any significant difference with that of shank segment. However, the average angular velocity of shank
segment decreased similarly to all of them from the deceleration to acceleration phase. Consequently, the knee joint extended during the
acceleration phase in the lower sprint velocity group. These results suggest that the elite sprinters can be hardly extended of the knee
during the acceleration phase due to the greater angular velocity of shank segment. This is likely that elite sprinters could be transferred
angular velocity of thigh segment effectively to the leg swing velocity.
References:
28 14 TH
ANNUAL CONGRESS OF THE EUROPEAN COLLEGE OF SPORT SCIENCE