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Relationships between Arm-Leg Coordination and Intra-Stroke Velocity Fluctuation in Breaststroke. Hideki Takagi, Teruo Nomura, Kohji Wakayoshi, Takeshi Matsui, Keisuke Okuno, Futoshi Ogita, Yasushi Ikuta, Yuji Ohgi Japan Amateur Swimming Federation, Medicine and Science Committee. INTRODUCTION.
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Relationships between Arm-Leg Coordination and Intra-Stroke Velocity Fluctuation in Breaststroke Hideki Takagi, Teruo Nomura, Kohji Wakayoshi, Takeshi Matsui, Keisuke Okuno, Futoshi Ogita, Yasushi Ikuta, Yuji Ohgi Japan Amateur Swimming Federation, Medicine and Science Committee
INTRODUCTION Men’s 100M Breaststroke Final 15th FINA World Sports Medicine Congress
PURPOSE To compare differences in arm-leg coordination and intra-stroke hip velocity fluctuation in breaststroke due to event and performance level for both male and female swimmers 15th FINA World Sports Medicine Congress
8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 METHOD Participants of the preliminary, semi-final and final race in 50, 100 and 200m breaststroke events in the 9th FINA World Swimming Championships Subjects: Only swimmers who swam 4 or 5 lane Eliminated group and Qualified group 46 males and 36 females Underwater Analysis: The 25m point from start 15th FINA World Sports Medicine Congress
3 2 4 4 5 1 3 1 1-2: Recovery 2-3: Glide 3-4: Out-sweep 4-5: In-sweep 1-2: Sweep 2-3: Lift & Glide 3-4: Recovery 2 Duration of arm stroke Duration of arm-propulsion Recovery1 Glide 1 In-sweep1 Glide2 Out-sweep1 Arm Recovery2 Leg In-sweep 2 In-sweep 1 Recovery 1 Lift & Glide 1 %SRT %SPT Duration of leg-propulsion Duration of leg stroke DEFINITION 15th FINA World Sports Medicine Congress
Minimum V %MinV= Mean V INTRA-STROKE HIP VELOCITY 4.8m Lane 4 Y X Z (0,0,0) 1.5m 0.245m 0.49m 0.6 m 0.49m 0.49m 0.49m 0.6 m 0.49m 0.245m CCD Camera2 CCD Camera1 Video Timer VCR Start Signal 15th FINA World Sports Medicine Congress
60% 50% 40% 30% 20% 10% 0% -10% -20% Eliminated Eliminated Eliminated Eliminated Eliminated Eliminated Qualified Qualified Qualified Qualified Qualified Qualified Female Male Female Male Female Male 50m 100m 200m %SPT and %SRT %SPT (simultaneous arm-leg propulsion time) %SRT (simultaneous arm-leg recovery time) 15th FINA World Sports Medicine Congress
HIP VELOCITY FLUCTUATION 2.5 100m Female 2.0 1.5 Velocity (m/s) 1.0 Eliminated 0.5 Qualified 0.0 100 0 10 20 30 40 50 60 70 80 90 100m Male 2.5 2.0 1.5 Velocity (m/s) Eliminated 1.0 Qualified 0.5 0.0 0 10 20 30 40 50 60 70 80 90 100 %Time 15th FINA World Sports Medicine Congress
DISCUSSION • As the event distance increased, the %SPT value decreased significantly and the qualified swimmers adopted a significantly smaller %SPT than the eliminated swimmers. • The %MinV of the Eliminated group was significant lower than for the Qualified group. A characteristic of better performing swimmers was the lesser reduction in velocity during the non-propulsive phase. 15th FINA World Sports Medicine Congress
CONCLUSION • To accomplish high performance, a key factor for longer events is not only a propulsive technique but also a drag-reduction technique during the non-propulsive phase. 15th FINA World Sports Medicine Congress
ACKNOELEDGEMENTS This research was supported by the Japanese Amateur Swimming Federation and a grant from the Japanese Institute of Sports Science 15th FINA World Sports Medicine Congress