BIOMECHANICS SUPPORT FOR ELITE BIOMECHANICS SUPPORT FOR ELITE SWIMMERS WITH A DISABILITYSWIMMERS WITH A DISABILITY

Carl Payton, Ph.DCarl Payton, Ph.D

MMU CheshireMMU CheshireDepartment of Exercise & Sport ScienceDepartment of Exercise & Sport Science

INTRODUCTIONINTRODUCTION

• Britain’s elite disability swimmers have access Britain’s elite disability swimmers have access to a coordinated network of support services to a coordinated network of support services including, since June 2000, biomechanics.including, since June 2000, biomechanics.

• Currently 43 swimmers on the World Class Currently 43 swimmers on the World Class Pathway programme who are eligible for Pathway programme who are eligible for biomechanics support.biomechanics support.

• Competitive swimmers with a disability are Competitive swimmers with a disability are classified according to their level of physical classified according to their level of physical impairment (S1-S10), visual impairment impairment (S1-S10), visual impairment (S11-S13) or learning difficulty (S14).(S11-S13) or learning difficulty (S14).

INTRODUCTIONINTRODUCTION

AIM OF PRESENTATION AIM OF PRESENTATION

To give an overview of the To give an overview of the biomechanics support services being biomechanics support services being

provided to GB Disability Swimming.provided to GB Disability Swimming.

BIOMECHANICALBIOMECHANICALASSESSMENTASSESSMENT

APPLIED APPLIED RESEARCHRESEARCH

COACHCOACHSUPPORTSUPPORT

Three complementary components of Three complementary components of the support provision: the support provision:

• Qualitative and quantitative assessment techniques are used to analyse Qualitative and quantitative assessment techniques are used to analyse swimmers in training and in competition.swimmers in training and in competition.

• Assessment opportunity at least once per macrocycle at a Regional or Assessment opportunity at least once per macrocycle at a Regional or National High Performance Centre, and also in competition.National High Performance Centre, and also in competition.

• Four main types of analysis are undertaken:Four main types of analysis are undertaken:

BIOMECHANICAL ASSESSMENTBIOMECHANICAL ASSESSMENT

1.1. Video Analysis Video Analysis

2.2. Velocity Meter AnalysisVelocity Meter Analysis

3.3. Tethered Force Analysis Tethered Force Analysis

4.4. Race (competition) Analysis Race (competition) Analysis

• Initial ‘Assessment’ involves filming of Initial ‘Assessment’ involves filming of starts, turns and strokes, followed by one-starts, turns and strokes, followed by one-to-one feedback session to identify to-one feedback session to identify strengths and weaknesses.strengths and weaknesses.

• Basic performance parameters, e.g. stroke Basic performance parameters, e.g. stroke rate, stroke length, are derived from the rate, stroke length, are derived from the video recordings.video recordings.

1. Video Analysis1. Video Analysis

BIOMECHANICAL ASSESSMENTBIOMECHANICAL ASSESSMENT

• ‘‘Intervention’ sessions are used Intervention’ sessions are used subsequently to monitor progress and subsequently to monitor progress and provide immediate feedback for fault provide immediate feedback for fault correction.correction.

• Focus on only one or two aspects of Focus on only one or two aspects of technique, identified by the coach and technique, identified by the coach and biomechanist as being priority areas.biomechanist as being priority areas.

2. Velocity Meter 2. Velocity Meter AnalysisAnalysis

BIOMECHANICAL ASSESSMENTBIOMECHANICAL ASSESSMENT

• Measures the instantaneous speed of a Measures the instantaneous speed of a swimmer, continuously and in real time.swimmer, continuously and in real time.

• The device is The device is portable, accurate and causes portable, accurate and causes minimal disturbance to the swimmer. minimal disturbance to the swimmer.

Applications:Applications:

• Quantifying stroke imbalance in amputees;Quantifying stroke imbalance in amputees;

• Measuring streamlining ability;Measuring streamlining ability;

• Monitoring speed fluctuations in Monitoring speed fluctuations in breaststroke;breaststroke;

• Identifying optimum stroke rates in Identifying optimum stroke rates in breaststroke.breaststroke.

BIOMECHANICAL ASSESSMENTBIOMECHANICAL ASSESSMENT

3. Tethered Force 3. Tethered Force AnalysisAnalysis• A number of tethered swimming protocols A number of tethered swimming protocols

are currently being piloted.are currently being piloted.

• Aim of developing a swimming-specific test Aim of developing a swimming-specific test for anaerobic power. for anaerobic power.

• Semi-tethered ergometer under development Semi-tethered ergometer under development that will measure force and external power that will measure force and external power under more ecologically valid conditions.under more ecologically valid conditions. Fully tethered swimmingFully tethered swimming

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Semi-tethered swimming ergometerSemi-tethered swimming ergometer

• Enables key performance parameters Enables key performance parameters (start time, turn time, swim speed, (start time, turn time, swim speed, stroke length, stroke rate) to be stroke length, stroke rate) to be measured in competition. measured in competition.

Swimmer A's Speed during his 100 m Breaststroke heat (blue) and final (red) at the 2003 British LC Championships

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4. Race (competition) Analysis4. Race (competition) Analysis

• Information helps coach to:Information helps coach to: Identify their swimmer’s strengths Identify their swimmer’s strengths

and weaknesses;and weaknesses; Plan race strategy;Plan race strategy; Monitor progress in race skills, Monitor progress in race skills,

e.g. starts and turns;e.g. starts and turns; Identify changes in stroke Identify changes in stroke

‘efficiency’ (velocity ‘efficiency’ (velocity SL). SL).

BIOMECHANICAL ASSESSMENTBIOMECHANICAL ASSESSMENT

APPLIED RESEARCHAPPLIED RESEARCH

• Applied research is an essential component of Applied research is an essential component of the biomechanics support work. the biomechanics support work.

• Focus is on performance optimisation of Focus is on performance optimisation of specific disability groups. One example will be specific disability groups. One example will be presented here; the presented here; the arm amputee projectarm amputee project..

• Currently 10 single arm (at elbow) amputees Currently 10 single arm (at elbow) amputees on the WCP programme. on the WCP programme.

• A number of approaches are being usedA number of approaches are being used to identifyidentify the performance limiting factors for he performance limiting factors for these swimmers :these swimmers :

2D and 3D Video Analysis; 2D and 3D Video Analysis;

Computational Fluid Dynamics (CFD); Computational Fluid Dynamics (CFD);

Isokinetic Dynamometry.Isokinetic Dynamometry.

APPLIED RESEARCHAPPLIED RESEARCH

2D and 3D Video Analysis2D and 3D Video Analysis

• Considerable inter- and intra- swimmer Considerable inter- and intra- swimmer variability in arm coordination during arm variability in arm coordination during arm amputee front crawl swimming. amputee front crawl swimming.

• An adaptedAn adapted Index of Coordination Index of Coordination (IdC)(IdC) is is being used to quantify this variability and being used to quantify this variability and to help establish the most effective to help establish the most effective coordination. coordination.

• 3D video analysis being used to assess 3D video analysis being used to assess effects of the breathing action, body roll, effects of the breathing action, body roll, arm pull pattern and leg kick, on arm pull pattern and leg kick, on swimming performance.swimming performance.

• 2D and 3D video data are also being used 2D and 3D video data are also being used for input into computer simulation models.for input into computer simulation models.

Effect of swim speed on adapted IdC Effect of swim speed on adapted IdC

Computational Fluid Dynamics (CFD)Computational Fluid Dynamics (CFD)

• CFD is a technique that allows the user to CFD is a technique that allows the user to simulate fluid flow around a model to study simulate fluid flow around a model to study the fluid forces (e.g. propulsion) acting.the fluid forces (e.g. propulsion) acting.

APPLIED RESEARCHAPPLIED RESEARCH

3D model of amputee arm• Computer models developed using data Computer models developed using data from 3D laser scanning of amputee from 3D laser scanning of amputee swimmers.swimmers.

• Video-derived kinematic data are used to Video-derived kinematic data are used to describe the swimmer’s motion.describe the swimmer’s motion.

• Fluent 6.3 used to study the effect of body Fluent 6.3 used to study the effect of body roll, shoulder extension velocity and level roll, shoulder extension velocity and level of amputation (above or below elbow) on of amputation (above or below elbow) on propulsion. propulsion.

No RollRoll

Isokinetic DynamometryIsokinetic Dynamometry

• Hypothesised that the faster swimmers possess Hypothesised that the faster swimmers possess greater shoulder extension strength and less greater shoulder extension strength and less asymmetry. asymmetry.

• Dynamic shoulder extension strength of each arm Dynamic shoulder extension strength of each arm tested at slow (60tested at slow (60ss-1-1) and fast (180) and fast (180ss-1-1) speeds.) speeds.

• Shoulder of unaffected arm significantly stronger Shoulder of unaffected arm significantly stronger than shoulder of the affected arm, at both speeds.than shoulder of the affected arm, at both speeds.

• Considerable variability in the level of asymmetryConsiderable variability in the level of asymmetry

• No significant relationship between the shoulder No significant relationship between the shoulder strength, the level of asymmetry and the strength, the level of asymmetry and the performance level of the swimmer. performance level of the swimmer.

APPLIED RESEARCHAPPLIED RESEARCH

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Unaffected arm Affected arm

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COACH SUPPORTCOACH SUPPORT

• To extend the coaches’ knowledge of the To extend the coaches’ knowledge of the biomechanical factors that limit swimming biomechanical factors that limit swimming performance.performance.

• To enable coaches to interpret and utilise To enable coaches to interpret and utilise biomechanical information effectively.biomechanical information effectively.

• Coach support is delivered on the pool-deck Coach support is delivered on the pool-deck and in the classroom.and in the classroom.

• Theoretical and practical topics are covered Theoretical and practical topics are covered in ‘Delivering on Deck’ Workshops, Project in ‘Delivering on Deck’ Workshops, Project Notes and Handbook.Notes and Handbook.

Thank you for your attentionThank you for your attention

AcknowledgementsAcknowledgementsDr. Daniel Daly, Mr. Ian Kennedy, Mr. Gregory Lecrivain, Ms. Casey Lee, Dr. Daniel Daly, Mr. Ian Kennedy, Mr. Gregory Lecrivain, Ms. Casey Lee, Mr. Georgios Machtsiras, Mr. Tom McKee, Dr. Roozbeh Naemi, Mr. Conor Mr. Georgios Machtsiras, Mr. Tom McKee, Dr. Roozbeh Naemi, Mr. Conor Osborough, Mr. Des Richards, Mr. Grant Rockley, Professor Ross Sanders, Osborough, Mr. Des Richards, Mr. Grant Rockley, Professor Ross Sanders,

Dr. Arezki Slaouti, UK Sport, British Swimming, BPA, MMUDr. Arezki Slaouti, UK Sport, British Swimming, BPA, MMU