codamotion Motion Times Issue 1 2008 published by Raven2 Ltd, Waverley House, BeaumarisIsle of Anglesey, LL58 8EGinfo@raven2.co.uk Tel: 01248 811449

The accuracy of the content of articles supplied for inclusion in Motion Times is not the responsibility of the publishercodamotion: info@codamotion.com

4

DR. MICHAEL KOHSchool of Sports, Health and Leisure, Republic Polytechnic, SingaporeRepublic Polytechnic’s School of Sports, Healthand Leisure acquired the Codamotion motioncapture and analysis system in April this year.Since its commissioning, we have built up anintensive research agenda involving its use. Herein our human performance laboratory, we mentor

students from secondary schools in researchprojects involving gait analysis and orthoticsintervention. Two of our projects were awardeddistinctions in the mentoring programme hostedby the local Ministry of Education. Our otherprojects involve evaluating our markerlesstracking system against the Coda system; loadcarriage analysis on an instrumented treadmillintegrated with the Coda; and, drop jump analysesusing the Kistler force platform also integratedwith the Coda. We will be embarking on a newresearch agenda on sports technique analyses in10-pin bowling, golf swing analyses and injurymanagement programmes in the new year.

UNA NI MHAININ, KIERAN O SULLIVANDept. of Physiotherapy,University of Limerick, Ireland Low dye (LD) taping is a commonly usedphysiotherapy technique to treat symptoms inthe lower limb related to excessive pronation.Various measures of pronation includingvertical navicular height, navicular drop,plantar pressure patterns and 2D video analysishave been used to assess the effectiveness ofLD taping in subjects with excessive pronation.However no studies have previouslyinvestigated the effects of LD taping at thesubtalar joint using 3-D analysis. The aim ofthis study was to investigate the effects of LDtaping on pronation, supination and total range

of motion at the subtalar joint in healthysubjects with increased pronation using 3-DCODA motion analysis. A convenience sampleof 20 healthy university staff and studentsparticipated in the study. A repeated measurescrossover study design was used, wheresubjects were assessed under both taped andnon-taped condition. Pronation, supination,mean joint position and total subtalar ROMwere analysed and compared between the twoconditions. Descriptive statistics were used todetermine whether differences at the subtalarjoint under both conditions were statisticallysignificant. The results demonstratedstatistically significant differences were foundbetween taped and non-taped conditions forpronation, supination and total subtalar ROM.

Pronation (p<0.05) supination (p<0.05) andtotal subtalar joint ROM (p<0.05) decreasedsignificantly under the taped conditioncompared to the non-taped condition. Nostatistically significant differences werehowever found between taped and non-tapedconditions for mean subtalar joint position.These findings support previous researchfindings that suggest that LD taping reducespronation at the subtalar joint. It also appears,however, that LD taping reduces supinationand overall ROM at the subtalar joint.Therefore, the mechanism of action may bemore related to limiting mobility in general,rather than having a specific anti-pronationeffect at the sub-talar joint. Key words: Taping,CODA, pronation, subtalar

Movement Analysis in Singapore

Journal for the motion-capture community Issue 1-08

1

Full body motion analysis of triprecovery in younger and older adultsDR. PAULIEN ROOS, DR. POLLY MCGUIGANAND DR. GRANT TREWARTHA,Sport and Exercise Science Research Group, School for Health, University of Bath, Bath, UK

This research has set out to better understandwhy some people fall after they trip, whileothers are able to regain their balance. This knowledge will provide importantinformation for fall prevention practices andreduce the number of falls in older adults.Falls in older adults are a major problem, asabout one in every three adults aged over 65 fallat least once a year [1]. Most falls in olderadults are caused by tripping over an obstacle,such as a kerb or uneven pavement whenwalking outdoors, or loose carpets or cables athome. These falls have large health, social andeconomical costs.

We compared tripping responses of a group ofnine younger women (aged 20 to 35 years) witha group of eight older women (aged 65 to 75years). We wanted to investigate the influenceof the lower limbs as well as the arms on trip

recovery success. Movements during triprecovery occur in planes, therefore three-dimensional full body kinematic data werecollected at 200 Hz with the Coda cx1 system(Charnwood Dynamics Ltd.). A total of 27markers were used in a combination of acustom triad set-up and the Codamotionsegmental gait analysis marker set. The markersetup is shown in the figure below. In statictrials, the relative positions of the joint centresto the triad markers were recorded. For dynamictrials, virtual markers were defined based onthis information. This specific set-up wasdefined to be able to measure three-dimensionalkinematics with the use of a single scanner.Additional measurements taken were groundreaction forces with a force plate (Kistler9287BA), to be able to calculate the jointmoments at the lower limbs, and muscleactivity with EMG (Noraxon, Telemyo).In the experimental protocol the women walkedover a walkway and they were tripped inrandom trials. A tripping device was customdesigned for this experiment. This deviceconsisted of plates that could be rotatedupwards and obstruct either the left or right footto cause a trip. To ensure the participants couldnot fall if they were unable to recover from atrip, all participants were secured in a safetyharness that was attached to an overhead rail.The outcomes of this research showed thatyounger adults used their arms effectivelyduring trip recovery to prevent them fromfalling. Older adults on the contrary used theirarms in a more protective way and reachedforward to arrest a possible fall [2]. Thisresearch also showed that older adults were notas effective as younger adults in using theirrecovery limb to prevent falling after a trip andin some occasions selected a different recoverystrategy [3]. Possible underlying reasons for thisare muscle strength, movement speed andplacement of the recovery limb. These are at themoment being further investigated. Ourresearch group uses a combination ofexperiments and computer simulations in thisresearch and a computer model has beendeveloped that simulates movements of trip

recovery [4]. The future goal is to develop anassessment tool that will assist in selection ofthe most appropriate fall prevention therapy forspecific individuals. This tool will be designedusing the experimental outcomes in combinationwith the computer simulation model.[1] Tinetti ME, Speechley M, Ginter SF. Risk-factors for falls among elderly persons living inthe community. New England Journal ofMedicine 1988;319(26):1701-7.[2] Roos PE, McGuigan MP, Kerwin DG,Trewartha G. The role of arm movement inearly trip recovery in younger and older adults.Gait & Posture in press.[3] Roos PE, McGuigan MP, Kerwin DG,Trewartha G. The role of the recovery limb intrip-recovery for younger and older adult. 4thInternational Biomechanics of the Lower Limbin Health and Disease & RehabilitationConference, 2007, Salford. [4] Roos PE, McGuigan MP, Kerwin DG,Trewartha G. Development and evaluation of acomputer simulation model of trip-recovery.XIth ISCSB conference, 2007, Taiwan: ISB.

The Effects of a Taping Technique on FootMotion and Joint Displacement During Gait

EEMCPDM 20084th East European and

Mediterranean Cerebral

Palsy and Developmental

Medicine Conference

Eilat, Israel,

May 28-31 2008Information and registration:

www.eemcpdm2008.com

The 2ndInternationalCongress on

GAIT & MENTALFUNCTION

Amsterdam,

The Netherlands,

February 1-3 2008Information and registration:

www.kenes.com/gait

Motion_Times_Issue_1_07 7/1/08 13:44 Page 4

Table 1: Mean RMS Differences in Touchdown (TD) and Take-off (TO) Times between Force Plate Criterion and Marker Derived Criterion from Three Experimental Conditionsacross Six Subjects.

32

Identification of Instants of Touchdownand Take-Off in Sprint RunningDR. IAN BEZODIS, ANDY THOMSON, DR. MARIANNE GITTOES & PROF. DAVID KERWINCardiff School of Sport,University of Wales Institute,Cardiff, UK

The identification of the instants oftouchdown and take-off are important indefining step characteristics in sprinting.Furthermore, previous studies of sprintinghave identified the magnitude of keykinematic variables at touchdown and take-offas being important indicators of performance.Examples include high knee flexion velocityat touchdown (Mann & Herman, 1985) andreduced hip extension angle at take-off (Kunz& Kaufmann, 1981). The purpose of thisstudy was to evaluate the accuracy indetermining the instants of touchdown andtake-off during a sprint run using a singleCODA motion scanner unit, based on:(i) The vertical displacement of toe markersfrom a standing trial;(ii) The peak vertical acceleration as athreshold value for ground contact. MethodsSix athletes (5 male, 1 female; age 22.8 ± 1.6years, body mass 75.5 ± 9.4 kg; height

1.78 ± 0.06 m) participated in the study. Asillustrated in Figure 1a, active CODA markers(800 Hz) were positioned on the lateral aspectof each subject’s left sprinting shoe, at fivesites. Two static, standing trials (flat feet andtip-toed), where position data were collectedusing a CODA motion analysis system(6.69G-CX1/MPX30) were acquired for eachsubject (capture time: 10 s). Subjects thencompleted ten running trials, in which a single

foot contact was made with a force plate(1000 Hz, 9287BA, Kistler Instruments Ltd.,Switzerland). A second series of two standingand ten sprint trials was performed in whichmarkers were attached to the medial aspect ofthe shoe (Figure 1b). Vertical ground reaction force, marker positionand marker acceleration data (low pass filtered at20 Hz) for all static and sprint running trials wereexported at 800 Hz for further analysis. Criteria

Marker Marker RMS Differences with respect to Force Plate Criterion [s]

Lateral

Medial

ABCDEFGHIJ

TD0.0070.0050.0150.0030.0040.0050.0470.0130.0070.017

TO0.0150.0080.0060.0120.0480.0150.0090.0050.0090.030

TD0.0260.0470.0330.0230.0040.0310.0250.0350.0190.013

TO0.0120.0080.0040.0240.0400.0110.0060.0090.0150.026

TD0.0060.0050.0070.0050.0050.0070.0070.0070.0070.007

TO0.0090.0170.0070.0220.0090.0090.0080.0070.0060.008

Flat-footedCoordinate

Tip-toedCoordinate

VerticalAcceleration

b)a)

VITOMIR RACICDept. of Civil & Structural Engineering,University of Sheffield, Sheffield, UK

The Vibration Engineering Section in theDepartment of Civil & Structural Engineering,University of Sheffield, is utilising theCodamotion (Charnwood Dynamics, UK) andADAL3D (Medical Development, France)instrumented treadmill to study how peoplewalking and running affect slender civilengineering structures, such as footbridges, floorsand staircases, prone to vibrations when occupiedand dynamically excited by humans.Of all dynamic forces induced by humans, suchas jumping, bouncing/bobbing and swaying, thedynamic forces induced by human walking andrunning are the least understood and mostcomplex to deal with when consideringperformance of civil engineering structures thatare dynamically excited by these activities. Thisis because they change simultaneously in timeand space, being random in nature and varyingconsiderably not only between different peoplebut also for a single individual who cannot repeattwo identical steps. The variations in how people

walk and run make the effect of such movementson engineering structures unpredictable and haveto be quantified in order to provide adequateguidance to designers. There are varied opinionson the extent to which the constrained motion ona treadmill can represent normal walking. Hencedata on variability and statistics of the loadsinduced by individuals and groups when walkingand running will be gathered using theCodamotion tracking system. There are two keynovelties in the proposed approach:(1) utilisation of 'free field' measurement ofthree-component continuous walking/runningforces by measuring movement of the humanbody or bodies without artificial restrictionssuch as handrails or the controlled speed of the

treadmill belt. Procedures for identifying theseforces will be calibrated by comparison withstandard direct measurement of forces on atreadmill.(2) the investigators aim to establish a databaseof measured time-varying traces ofwalking/running forces to develop stochasticmodels that can predict more realistically thevibration behaviour of real-life structures underpedestrian-induced excitation leading to morerational and efficient designs.The project is fully funded by UKGovernment's Engineering and PhysicalSciences Research Council (EPSRC, referenceNo. EP/E018734/1). Contacts: Prof. James MWBrownjohn james.brownjohn@sheffield.ac.uk

Human walking and running forces:novel experimental characterisation and application in civilengineering dynamics

for touchdown and take-off were determinedfrom force data. Marker derived touchdown andtake-off times were determined using thestanding trials as a criterion and, separately, usingpeak vertical acceleration. Mean RMSdifferences across all subjects between forceplate and marker derived criteria were calculated. ResultsMean RMS differences across six subjects foreach condition are displayed in Table 1. The lowest individual RMS differences betweenthe criterion measure and marker derived eventtime occurred when using coordinates from thestatic trials.DiscussionThe instants of touchdown and take-off duringsprint running contacts could be determined tobetween 0.003 and 0.005 s of the force data-derived criterion measure when usingcoordinate data of lateral and medial footmarkers. The presented RMS differences wereequivalent to a resolution of measurement ofat least 200 Hz. This provided a similar levelof accuracy to that reported by Hunter et al.

(2004), who identified the instant oftouchdown to within one field at 240 Hz in93% of trials when using the method ofHreljac and Marshall (2000). The findings ofthis study suggest that two markers locatedon each of the lateral and medial aspects ofthe foot could be used to identify the instantsof sprint running touchdown and take-off.Lateral and medial marker sets of the footwere necessary to accommodate laboratory-based data collections in which a unilateralCODA scanner was used to track bilateralsagittal plane motions. The peak verticalacceleration threshold could be used when thecollection of a standing trial is not possible;for example, the vertical displacementthreshold for sprint contacts on a bankedcurve may be difficult to derive.ConclusionIdentification of contact events are important for the determination of stepcharacteristics and event-specific kinematics during sprint runningperformances. Using vertical displacements

of foot markers, touchdown and take-offevents in sprinting could be identified tobetween 0.003 and 0.005 s of a force dataderived criterion measure.References1. Hreljac, A. & Marshall, R.N. (2000). Algorithms todetermine event timing during normal walking usingkinematic data. Journal of Biomechanics, 33 (6), 783-786.

2. Hunter, J.P., Marshall, R.N. & McNair, P.J. (2004).Interaction of step length and step rate during sprintrunning. Medicine and Science in Sports andExercise, 36 (2), 261-271.

3. Kunz, H. & Kaufmann, D.A. (1981). BiomechanicalAnalysis of Sprinting: Decathletes VersusChampions. British Journal of Sports Medicine, 15(3), 177-181.

4. Mann, R.V. & Herman, J. (1985). KinematicAnalysis of Olympic Sprint Performance: Men's 200Meters. International Journal of Sport Biomechanics,1, 151-162.

Figure 1.The lateral (a) and medial (b) locations of the CODA markers on the sprinting shoe prior to secure attachment of wires.Marker locations: superior to the distal end of the first toe [A]; lateral to the distal end of the third toe [B]; superior to thefirst interphalangeal joint of the second toe [C]; lateral to the distal end of the fifth toe [D] and lateral to the fifthmetatarsophalangeal joint [E]; superior to the distal end of the first toe [F]; medial to the distal end of the first toe [G];superior to the first inter-phalangeal joint of the second toe [H]; medial to the first inter-phalangeal joint of the first toe[J] and medial to the first metatarso-phalangeal joint [K].

Motion_Times_Issue_1_07 7/1/08 13:44 Page 2

Table 1: Mean RMS Differences in Touchdown (TD) and Take-off (TO) Times between Force Plate Criterion and Marker Derived Criterion from Three Experimental Conditionsacross Six Subjects.

32

Identification of Instants of Touchdownand Take-Off in Sprint RunningDR. IAN BEZODIS, ANDY THOMSON, DR. MARIANNE GITTOES & PROF. DAVID KERWINCardiff School of Sport,University of Wales Institute,Cardiff, UK

The identification of the instants oftouchdown and take-off are important indefining step characteristics in sprinting.Furthermore, previous studies of sprintinghave identified the magnitude of keykinematic variables at touchdown and take-offas being important indicators of performance.Examples include high knee flexion velocityat touchdown (Mann & Herman, 1985) andreduced hip extension angle at take-off (Kunz& Kaufmann, 1981). The purpose of thisstudy was to evaluate the accuracy indetermining the instants of touchdown andtake-off during a sprint run using a singleCODA motion scanner unit, based on:(i) The vertical displacement of toe markersfrom a standing trial;(ii) The peak vertical acceleration as athreshold value for ground contact. MethodsSix athletes (5 male, 1 female; age 22.8 ± 1.6years, body mass 75.5 ± 9.4 kg; height

1.78 ± 0.06 m) participated in the study. Asillustrated in Figure 1a, active CODA markers(800 Hz) were positioned on the lateral aspectof each subject’s left sprinting shoe, at fivesites. Two static, standing trials (flat feet andtip-toed), where position data were collectedusing a CODA motion analysis system(6.69G-CX1/MPX30) were acquired for eachsubject (capture time: 10 s). Subjects thencompleted ten running trials, in which a single

foot contact was made with a force plate(1000 Hz, 9287BA, Kistler Instruments Ltd.,Switzerland). A second series of two standingand ten sprint trials was performed in whichmarkers were attached to the medial aspect ofthe shoe (Figure 1b). Vertical ground reaction force, marker positionand marker acceleration data (low pass filtered at20 Hz) for all static and sprint running trials wereexported at 800 Hz for further analysis. Criteria

Marker Marker RMS Differences with respect to Force Plate Criterion [s]

Lateral

Medial

ABCDEFGHIJ

TD0.0070.0050.0150.0030.0040.0050.0470.0130.0070.017

TO0.0150.0080.0060.0120.0480.0150.0090.0050.0090.030

TD0.0260.0470.0330.0230.0040.0310.0250.0350.0190.013

TO0.0120.0080.0040.0240.0400.0110.0060.0090.0150.026

TD0.0060.0050.0070.0050.0050.0070.0070.0070.0070.007

TO0.0090.0170.0070.0220.0090.0090.0080.0070.0060.008

Flat-footedCoordinate

Tip-toedCoordinate

VerticalAcceleration

b)a)

VITOMIR RACICDept. of Civil & Structural Engineering,University of Sheffield, Sheffield, UK

The Vibration Engineering Section in theDepartment of Civil & Structural Engineering,University of Sheffield, is utilising theCodamotion (Charnwood Dynamics, UK) andADAL3D (Medical Development, France)instrumented treadmill to study how peoplewalking and running affect slender civilengineering structures, such as footbridges, floorsand staircases, prone to vibrations when occupiedand dynamically excited by humans.Of all dynamic forces induced by humans, suchas jumping, bouncing/bobbing and swaying, thedynamic forces induced by human walking andrunning are the least understood and mostcomplex to deal with when consideringperformance of civil engineering structures thatare dynamically excited by these activities. Thisis because they change simultaneously in timeand space, being random in nature and varyingconsiderably not only between different peoplebut also for a single individual who cannot repeattwo identical steps. The variations in how people

walk and run make the effect of such movementson engineering structures unpredictable and haveto be quantified in order to provide adequateguidance to designers. There are varied opinionson the extent to which the constrained motion ona treadmill can represent normal walking. Hencedata on variability and statistics of the loadsinduced by individuals and groups when walkingand running will be gathered using theCodamotion tracking system. There are two keynovelties in the proposed approach:(1) utilisation of 'free field' measurement ofthree-component continuous walking/runningforces by measuring movement of the humanbody or bodies without artificial restrictionssuch as handrails or the controlled speed of the

treadmill belt. Procedures for identifying theseforces will be calibrated by comparison withstandard direct measurement of forces on atreadmill.(2) the investigators aim to establish a databaseof measured time-varying traces ofwalking/running forces to develop stochasticmodels that can predict more realistically thevibration behaviour of real-life structures underpedestrian-induced excitation leading to morerational and efficient designs.The project is fully funded by UKGovernment's Engineering and PhysicalSciences Research Council (EPSRC, referenceNo. EP/E018734/1). Contacts: Prof. James MWBrownjohn james.brownjohn@sheffield.ac.uk

Human walking and running forces:novel experimental characterisation and application in civilengineering dynamics

for touchdown and take-off were determinedfrom force data. Marker derived touchdown andtake-off times were determined using thestanding trials as a criterion and, separately, usingpeak vertical acceleration. Mean RMSdifferences across all subjects between forceplate and marker derived criteria were calculated. ResultsMean RMS differences across six subjects foreach condition are displayed in Table 1. The lowest individual RMS differences betweenthe criterion measure and marker derived eventtime occurred when using coordinates from thestatic trials.DiscussionThe instants of touchdown and take-off duringsprint running contacts could be determined tobetween 0.003 and 0.005 s of the force data-derived criterion measure when usingcoordinate data of lateral and medial footmarkers. The presented RMS differences wereequivalent to a resolution of measurement ofat least 200 Hz. This provided a similar levelof accuracy to that reported by Hunter et al.

(2004), who identified the instant oftouchdown to within one field at 240 Hz in93% of trials when using the method ofHreljac and Marshall (2000). The findings ofthis study suggest that two markers locatedon each of the lateral and medial aspects ofthe foot could be used to identify the instantsof sprint running touchdown and take-off.Lateral and medial marker sets of the footwere necessary to accommodate laboratory-based data collections in which a unilateralCODA scanner was used to track bilateralsagittal plane motions. The peak verticalacceleration threshold could be used when thecollection of a standing trial is not possible;for example, the vertical displacementthreshold for sprint contacts on a bankedcurve may be difficult to derive.ConclusionIdentification of contact events are important for the determination of stepcharacteristics and event-specific kinematics during sprint runningperformances. Using vertical displacements

of foot markers, touchdown and take-offevents in sprinting could be identified tobetween 0.003 and 0.005 s of a force dataderived criterion measure.References1. Hreljac, A. & Marshall, R.N. (2000). Algorithms todetermine event timing during normal walking usingkinematic data. Journal of Biomechanics, 33 (6), 783-786.

2. Hunter, J.P., Marshall, R.N. & McNair, P.J. (2004).Interaction of step length and step rate during sprintrunning. Medicine and Science in Sports andExercise, 36 (2), 261-271.

3. Kunz, H. & Kaufmann, D.A. (1981). BiomechanicalAnalysis of Sprinting: Decathletes VersusChampions. British Journal of Sports Medicine, 15(3), 177-181.

4. Mann, R.V. & Herman, J. (1985). KinematicAnalysis of Olympic Sprint Performance: Men's 200Meters. International Journal of Sport Biomechanics,1, 151-162.

Figure 1.The lateral (a) and medial (b) locations of the CODA markers on the sprinting shoe prior to secure attachment of wires.Marker locations: superior to the distal end of the first toe [A]; lateral to the distal end of the third toe [B]; superior to thefirst interphalangeal joint of the second toe [C]; lateral to the distal end of the fifth toe [D] and lateral to the fifthmetatarsophalangeal joint [E]; superior to the distal end of the first toe [F]; medial to the distal end of the first toe [G];superior to the first inter-phalangeal joint of the second toe [H]; medial to the first inter-phalangeal joint of the first toe[J] and medial to the first metatarso-phalangeal joint [K].

Motion_Times_Issue_1_07 7/1/08 13:44 Page 2

codamotion Motion Times Issue 1 2008 published by Raven2 Ltd, Waverley House, BeaumarisIsle of Anglesey, LL58 8EGinfo@raven2.co.uk Tel: 01248 811449

The accuracy of the content of articles supplied for inclusion in Motion Times is not the responsibility of the publishercodamotion: info@codamotion.com

4

DR. MICHAEL KOHSchool of Sports, Health and Leisure, Republic Polytechnic, SingaporeRepublic Polytechnic’s School of Sports, Healthand Leisure acquired the Codamotion motioncapture and analysis system in April this year.Since its commissioning, we have built up anintensive research agenda involving its use. Herein our human performance laboratory, we mentor

students from secondary schools in researchprojects involving gait analysis and orthoticsintervention. Two of our projects were awardeddistinctions in the mentoring programme hostedby the local Ministry of Education. Our otherprojects involve evaluating our markerlesstracking system against the Coda system; loadcarriage analysis on an instrumented treadmillintegrated with the Coda; and, drop jump analysesusing the Kistler force platform also integratedwith the Coda. We will be embarking on a newresearch agenda on sports technique analyses in10-pin bowling, golf swing analyses and injurymanagement programmes in the new year.

UNA NI MHAININ, KIERAN O SULLIVANDept. of Physiotherapy,University of Limerick, Ireland Low dye (LD) taping is a commonly usedphysiotherapy technique to treat symptoms inthe lower limb related to excessive pronation.Various measures of pronation includingvertical navicular height, navicular drop,plantar pressure patterns and 2D video analysishave been used to assess the effectiveness ofLD taping in subjects with excessive pronation.However no studies have previouslyinvestigated the effects of LD taping at thesubtalar joint using 3-D analysis. The aim ofthis study was to investigate the effects of LDtaping on pronation, supination and total range

of motion at the subtalar joint in healthysubjects with increased pronation using 3-DCODA motion analysis. A convenience sampleof 20 healthy university staff and studentsparticipated in the study. A repeated measurescrossover study design was used, wheresubjects were assessed under both taped andnon-taped condition. Pronation, supination,mean joint position and total subtalar ROMwere analysed and compared between the twoconditions. Descriptive statistics were used todetermine whether differences at the subtalarjoint under both conditions were statisticallysignificant. The results demonstratedstatistically significant differences were foundbetween taped and non-taped conditions forpronation, supination and total subtalar ROM.

Pronation (p<0.05) supination (p<0.05) andtotal subtalar joint ROM (p<0.05) decreasedsignificantly under the taped conditioncompared to the non-taped condition. Nostatistically significant differences werehowever found between taped and non-tapedconditions for mean subtalar joint position.These findings support previous researchfindings that suggest that LD taping reducespronation at the subtalar joint. It also appears,however, that LD taping reduces supinationand overall ROM at the subtalar joint.Therefore, the mechanism of action may bemore related to limiting mobility in general,rather than having a specific anti-pronationeffect at the sub-talar joint. Key words: Taping,CODA, pronation, subtalar

Movement Analysis in Singapore

Journal for the motion-capture community Issue 1-08

1

Full body motion analysis of triprecovery in younger and older adultsDR. PAULIEN ROOS, DR. POLLY MCGUIGANAND DR. GRANT TREWARTHA,Sport and Exercise Science Research Group, School for Health, University of Bath, Bath, UK

This research has set out to better understandwhy some people fall after they trip, whileothers are able to regain their balance. This knowledge will provide importantinformation for fall prevention practices andreduce the number of falls in older adults.Falls in older adults are a major problem, asabout one in every three adults aged over 65 fallat least once a year [1]. Most falls in olderadults are caused by tripping over an obstacle,such as a kerb or uneven pavement whenwalking outdoors, or loose carpets or cables athome. These falls have large health, social andeconomical costs.

We compared tripping responses of a group ofnine younger women (aged 20 to 35 years) witha group of eight older women (aged 65 to 75years). We wanted to investigate the influenceof the lower limbs as well as the arms on trip

recovery success. Movements during triprecovery occur in planes, therefore three-dimensional full body kinematic data werecollected at 200 Hz with the Coda cx1 system(Charnwood Dynamics Ltd.). A total of 27markers were used in a combination of acustom triad set-up and the Codamotionsegmental gait analysis marker set. The markersetup is shown in the figure below. In statictrials, the relative positions of the joint centresto the triad markers were recorded. For dynamictrials, virtual markers were defined based onthis information. This specific set-up wasdefined to be able to measure three-dimensionalkinematics with the use of a single scanner.Additional measurements taken were groundreaction forces with a force plate (Kistler9287BA), to be able to calculate the jointmoments at the lower limbs, and muscleactivity with EMG (Noraxon, Telemyo).In the experimental protocol the women walkedover a walkway and they were tripped inrandom trials. A tripping device was customdesigned for this experiment. This deviceconsisted of plates that could be rotatedupwards and obstruct either the left or right footto cause a trip. To ensure the participants couldnot fall if they were unable to recover from atrip, all participants were secured in a safetyharness that was attached to an overhead rail.The outcomes of this research showed thatyounger adults used their arms effectivelyduring trip recovery to prevent them fromfalling. Older adults on the contrary used theirarms in a more protective way and reachedforward to arrest a possible fall [2]. Thisresearch also showed that older adults were notas effective as younger adults in using theirrecovery limb to prevent falling after a trip andin some occasions selected a different recoverystrategy [3]. Possible underlying reasons for thisare muscle strength, movement speed andplacement of the recovery limb. These are at themoment being further investigated. Ourresearch group uses a combination ofexperiments and computer simulations in thisresearch and a computer model has beendeveloped that simulates movements of trip

recovery [4]. The future goal is to develop anassessment tool that will assist in selection ofthe most appropriate fall prevention therapy forspecific individuals. This tool will be designedusing the experimental outcomes in combinationwith the computer simulation model.[1] Tinetti ME, Speechley M, Ginter SF. Risk-factors for falls among elderly persons living inthe community. New England Journal ofMedicine 1988;319(26):1701-7.[2] Roos PE, McGuigan MP, Kerwin DG,Trewartha G. The role of arm movement inearly trip recovery in younger and older adults.Gait & Posture in press.[3] Roos PE, McGuigan MP, Kerwin DG,Trewartha G. The role of the recovery limb intrip-recovery for younger and older adult. 4thInternational Biomechanics of the Lower Limbin Health and Disease & RehabilitationConference, 2007, Salford. [4] Roos PE, McGuigan MP, Kerwin DG,Trewartha G. Development and evaluation of acomputer simulation model of trip-recovery.XIth ISCSB conference, 2007, Taiwan: ISB.

The Effects of a Taping Technique on FootMotion and Joint Displacement During Gait

EEMCPDM 20084th East European and

Mediterranean Cerebral

Palsy and Developmental

Medicine Conference

Eilat, Israel,

May 28-31 2008Information and registration:

www.eemcpdm2008.com

The 2ndInternationalCongress on

GAIT & MENTALFUNCTION

Amsterdam,

The Netherlands,

February 1-3 2008Information and registration:

www.kenes.com/gait

Motion_Times_Issue_1_07 7/1/08 13:44 Page 4