injury management a biomechanical perspective...biomechanics of injury: summary technique understand...
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1Department of Housing and Public WorksDepartment of Housing and Public Works
Injury Management – A Biomechanical PerspectiveSimon Pearson
Queensland Academy of Sport
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Biomechanics of injury
▪ Injury▪ Load/force on tissue > tissue strength
▪ Acute (single catastrophic event) vs Chronic/Overuse
▪ Prevention▪ Understand risk areas
▪ High load relative to positional strength
▪ Adapt… position/load/strength
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Forces applied in swimming
▪ Morouço, Keskinen, Vilas-Boas & Fernandes (2011) - Relationship Between Tethered Forces and the Four Swimming Techniques Performance. Journal of Applied Biomechanics.
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Freestyle/Front Crawl and Shoulders
▪ Harrison, Cohen, Clearly, Mason & Pease (2014) - Torque and power about the joints of the arm during the freestyle stroke. XIIth International Symposium for Biomechanics and Medicine in Swimming.
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Freestyle/Front Crawl and Shoulders
▪ Harrison, Cohen, Clearly, Mason & Pease (2014) - Torque and power about the joints of the arm during the freestyle stroke. XIIth International Symposium for Biomechanics and Medicine in Swimming.
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Freestyle/Front Crawl and Shoulders
▪ Hand entry in line with shoulder
▪ Avoid excessive internal rotation of shoulder▪ Indicators: Hand pointing
out/thumb first entry
▪ Johnson, Gauvin & Fredericson (2003) – Swimming biomechanics and injury prevention. The physician and sports medicine 31(1).
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Freestyle/Front Crawl and Shoulders
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Freestyle/Front Crawl and Shoulders
▪ Not always as it seems…
▪ Weaker on the left
▪ Less propulsion on the left (strength and technical)
▪ Injured on the right
R L R RL L
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Breaststroke and knees
Leg outsw eep
Leg joinedArm recovery
Leg recovery
90° f lexion of leg
recoveryArm extension
Leg outsw eep
Leg extension
Hand outsw eep
Hand insw eep
90° f lexion of arm
recovery
0
0.5
1
1.5
2
2.5
3
0 20 40 60 80 100
Duration (% of one leg stroke)
Velo
city (
m.s
-1)
90° f lexion of leg
recoveryArm extension
Leg outsw eepLeg outsw eep
Leg extension
Leg joined
Hand outsw eep
Hand insw eep
Arm recovery
Leg recovery
90° f lexion of arm
recovery
0
0.5
1
1.5
2
2.5
3
0 20 40 60 80 100
Duration (% of one leg stroke)
Velo
city (
m.s
-1)
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▪ Primarily medial and anterior knee pain▪ High force in internally
rotated, flexed position
▪ Linked to hip abduction
▪ Highly associated with rapid increases and overall volume of breaststroke (kick)
▪ Imbalanced kick and compensatory overload
Breaststroke and knees
▪ Vizsolyi et al (1987) – Breaststroker’s knee: An analysis of epidemiological and biomechanical factors. American Journal of Sports Medicine 15(1).
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Biomechanics of injury: Summary
▪ Technique▪ Understand risk areas and try to correct and/or limit▪ Be aware changes in training load – movement specific not
just overall volume▪ Develop load on good technique (fatigue and technical failure)
▪ Strength▪ Actual forces are often not high in terms of overall lower
and upper body strength (peak ~60kg). Issue is application in end-range positions▪ Strength through range, not passive flexibility/range of motion▪ Develop joint stability and resilience