Journal of Rehabilitation Research and Development
tt tt tt tt tt
Rehabilitation R & D Progress Reports 1984
tt tt tt tt tt tt
VI. Biomechanics
tt
A. Joint Studies
tt
1. General
2. Lower Limb tt
3. Upper Limb tt
B. Spine
C. Human Locomotion and Gait Training
tt tt tt tt
D. Upper Limb Function
tt tt
E. Other
,Biomechanics
as ttwell ttas ttthe ttligament insertion sites.
VI.
tt tt tt
t t Biomechanical t t tests tton t t ulti-
Biomechanics
A. Joint Studies tt
1. General
Joint ttContracture:
Biomechanical-Clinical t t Correlates
Wayne t t H. t t Akeson
University ttof ttCalifornia
San tt Diego, ttCalifornia tt 92103
Sponsor: t t National t t Institutes tt of ttHealth
(National t t Institute t t of t t Arthritis, t t Diabetes, t t and
t t Digestive ttand ttKidney ttDiseases)
Current ttevidence ttsuggests ttthat ttstress-deprivation
tt effects tton ttsoft tttissues ttare ttprofound ttand ttoccur ttrapidly
tt and t t that t t recovery t t from t t stress t t deprivation t t is
t t quite tt slow. ttIn ttthis tt respect, tt recovery ttseems tt to
tt parallel ttthe tt effects tt of tt exercise tt on tt normal tt connective
tttissue. tt For tt example, tt our tt studies ttindicate ttthat tt a ttlarge
tt effort tt over tt a ttlong t t period t t of t t time t t is t t required
t t for t t a t t small t t hyper- tttrophy ttincrement tt of tttendons
t t or t t ligaments. t t The t t pur- tt pose tt of ttthe t t proposed
t t research t t program t t is ttto tt docu- tt ment tt further: tt (i) ttthe
ttfibrous tt connective tttissue tt mor- tt phological t t and
t t molecular t t changes t t resulting t t from tt stress
t t deprivation, t t and t t (ii) t t the t t consequent t t alteration
ttin tt physical tt characteristics. tt The tt answers ttto ttthese
tt questions t t are t t particularly t t important t t with
t t respect t t to ttthe tt development tt of ttthe tt rationale ttfor
tttreatment tt and tt rehabilitation tt of tt soft tttissue ttinjuries,
ttsuch tt as ttthe ttknee ttligaments.
A ttstandard ttinternal ttfixation ttmodel ttis ttused ttto ttinduce
ttstress-deprivation t t effects t t in t t rabbit t t knees.
t t Capsular tt and ttligamentous tt structures ttfrom ttthe tt model
tt are tt char- tt acterized tt by tt biomechanical, tt morphological,
tt biochem- ttical, tt and tt metabolic tt techniques tt on tt a
tt progressive tttime tt base t t during t t the t t development
t t of t t and t t recovery t t from ttthe tt stress-deprivation
ttstate. tt Hormone tt or tt drug tttreat- t t ment tt effects tt are tt also
tt evaluated ttfor tt efficacy ttin tt mod- tt ulating ttthe
tt development tt of tt and t t recovery ttfrom ttthe t t stress-
deprivation ttstate.
Biochemical t t analyses t t employed t t permit
t t evaluation
of ttcollagen ttturnover, tttotal ttproteoglycans, ttand ttcolla-
ttgen ttcross-link ttquantitation tt(reducible ttand
ttnonreduc- ttible). ttLight ttmicroscopy ttand tttransmission
ttEM ttare ttalso ttused ttto ttcharacterize ttmatrix ttand ttcells
104
, Rehabilitation RR&D Progress Reports 1984
tt supply. tt(ii) ttA ttflexor tttendon ttautograft ttwill t t be
mate ttstrength ttand ttstiffness ttof ttbone-ligament-bone
tt compared ttwith ttan ttallograft.
ttcomplex tt as tt well tt as ttthe tt mechanical tt properties tt of
In t t the t t first t t year, t t we t t will t t document t t the tt local
ttthe ttligament tt substance tt are tt performed. ttIn tt addition,
t t blood
tt ar- ttthrographic tt characterization tt of ttcontracture
ttstrength ttis tt assessed
Biomechanics ttof ttLigament/Tendon
ttRepairs ttand ttGrafts
Frank ttR. ttNoyes, ttM.D.
ttUniversity ttof ttCincinnati
ttCincinnati, ttOhio tt45267
Sponsor: t t National t t Institutes t t of t t Health
(National t t Institute t t of t t Arthritis, t t Diabetes, t t and
t t Digestive ttand t t Kidney t t Diseases)
It ttis ttour tthypothesis ttthat tthealing ttof ttligaments ttand
tttendons t t is t t a t t long-term t t process t t that t t involves
t t a t t return ttin t t strength t t due ttto ttcallus ttformation
ttfollowed t t by ttlong- ttterm tt remodeling tt of ttthe tt collagen,
ttinvolving tt changes ttin tt fiber tt alignment, tt ground
ttsubstance, tt and tt cross-linking. t t We t t further
t t hypothesize t t that t t the t t extent t t to t t which t t a
tt blood t t supply t t is t t available t t has t t a t t significant
t t effect t t on ttthe tt return ttin tt strength. tt Repairs ttin
ttrelatively tt vascular ttregions tt and ttfree tt grafts tt need
tt protection ttfor tt prolonged ttperiods tt of tttime. tt On ttthe
tt other tt hand, ttthe tt presence tt of tt a tt profuse t t vascular
t t supply t t may t t permit t t a t t more t t rapid tt return ttin
ttstrength, tt allowing tt earlier tt motion, tt earlier
ttrehabilitation, tt and tt return tt to tt normal tt activity tt with ttless
tt disuse tt effects.
To t t test t t these t t hypotheses, t t we t t will
t t measure t t the
return ttin ttstrength ttand ttbiochemical ttremodeling
ttover tttime ttof ttselected ttprimary ttrepairs ttand ttgrafts
ttin ttactivity ttconditioned, ttskeletally ttmature ttbeagles.
ttThe ttfollowing ttspecific ttsituations ttwill ttbe ttstudied.
Primary ttRepairs tt(i) ttWe ttwill ttcompare ttflexor-tendon
ttrepairs t t in t t highly t t vascular t t paratenon t t regions
t t with tt repairs ttin ttthe ttsynovial tt sheath, tt a
ttcomparatively tt avas- tt cular tt region. tt (ii) tt An tt anterior
ttcruciate tt mid-substance tt partial t t injury t t will t t be
t t studied t t with t t and t t without t t the t t use tt of tt a ttfat
tt pad tt sutured tt to ttthe ttligament ttto tt provide tt an
tt additional tt source tt of tt blood tt supply. tt(iii) ttHealing ttin
ttthe tt medical tt collateral ttligament tt will ttbe tt determined
ttfor tt complete tt mid-substance tttears ttinduced tt at ttthe
tttime tt of ttsurgery.
Grafts tt(i) t t A ttbone-lateral tttendon-bone ttfree ttgraft
ttsub- ttstitute ttfor ttthe ttanterior ttcruciate ttligament ttwill
ttbe ttcompared ttwith tt the ttsame ttgraft ttthat
ttincorporates tta tttissue ttflap ttthat ttprovides ttits ttblood
105
, Biomechanics
supply ttusing ttmicroangiography ttand ttrefine ttthe ttsurgi- ttgirdle ttby ttcombin- tting ttthe ttkinetics ttof ttthe ttaid ttwith
ttcal t t techniques, t t particularly t t to t t avoid
ttthe ttkinematics ttof ttthe ttupper ttlimb. ttThe ttcuffs ttof ttthe
ttelbow ttcrutches ttare ttalso ttgauged t t to t t evaluate
t t interruption t t of ttthe ttblood ttsupply. tt We tt will ttalso
t t the t t contribution t t of t t the t t cuff t t in
ttverify ttour ttexisting ttgripping ttmethods ttfor ttmechanical
tttesting ttof ttthe ttisolat- tted tttendons. ttDuring ttthe
ttsecond ttand ttthird ttyears ttof ttthe ttproject, ttwe ttwill
ttmeasure ttboth ttthe ttreturn ttin ttstrength ttand ttthe
ttbiochemical ttchanges ttin tteach ttmodel
2. Lower limb tt
Evaluation ttof ttJoint ttLoading
t tin ttthe ttUse ttof ttWalking ttAids
ttin
Total t t Hip t t Replacement t t Patients
K.A. t t Opila, t t B.Sc., t t and tt A.C. t t Nicol, t t Ph.D.
Bioengineering ttUnit
ttWolfson ttCentre
Glasgow t t G4 t t ONW, t t Scotland
Sponsor: t t University ttof ttStrathclyde
Abstract- ttThe ttimmediate ttresult ttof tttotal t t hip ttreplace-
tt ment t t surgery t t is t t a t t low-friction t t joint t t with
t t acetabular tt and t t femoral t t components t t rigidly
t t fixed t t in t t the t t pelvic ttand ttfemoral tt bones
ttrespectively. ttHowever, ttsoft tttissue tt damage t t results
t t in t t reduced t t abductor t t function t t as t t well tt as t t a
t t general t t tightness t t surrounding t t the t t hip t t joint.
Postoperative ttcare ttis tta ttcompromise; ttprotection
ttagainst ttsubluxation ttof ttthe ttjoint ttand tttearing ttof ttthe
ttabductor ttattachments ttversus ttthe ttneed ttto ttload ttthe
t t joint ttto ttreduce ttstiffness ttand ttbone ttand tttissue
ttatrophy. ttSurgeons ttvary ttin tttheir ttprescription ttof
tttherapy ttand ttwalking ttaids tt(which ttrange ttfrom
ttwalking ttframes ttto ttelbow ttcrutches ttto ttstick). ttSome
ttpatients ttare ttencour- ttaged ttto ttleave ttthe tthospital ttin
tt2 ttweeks ttwith ttno ttaids, ttwhile ttit ttis ttrecommended
ttthat ttothers ttuse ttat ttleast ttone ttstick ttup ttto tt6 ttmonths
ttpostoperatively.
The ttpurpose ttof ttthis ttstudy ttis ttto ttobtain
ttbiomechani- ttcal ttparameters ttof ttaided ttgait ttthat ttcan
ttbe ttconsidered ttwhen ttprescribing ttan ttaid ttand ttit ttuse,
ttin ttorder ttto ttoptimize tt patient ttmobility ttand ttjoint
ttprotection.
The tttypes ttof ttaids ttbeing ttstudied ttare ttelbow
ttcrutches ttand tt walking ttsticks. ttBesides ttthe tttype ttof
ttaid, ttthe tttechnique ttused ttto ttmeasure ttfor ttthe ttlength
ttof ttthe ttaid ttis ttbeing ttevaluated.
The ttanalysis ttfocuses tton ttboth ttthe ttupper ttand
ttlower ttlimbs. tt The ttshafts ttof ttthe ttaids ttare ttstrain-
gauged ttfor ttdetermination ttof ttthree ttforces. ttParticular
ttattention ttis ttgiven ttto ttthe ttloading ttof ttthe ttshoulder
106
tt tt tt tt tt
Rehabilitation R & D Progress Reports 1984
tt tt tt tt tt tt
VI. Biomechanics
tt
A. Joint Studies
tt
1. General
2. Lower Limb tt
3. Upper Limb tt
B. Spine
C. Human Locomotion and Gait Training
tt tt tt tt
D. Upper Limb Function
tt tt
E. Other
,Biomechanics
as ttwell ttas ttthe ttligament insertion sites.
VI.
tt tt tt
t t Biomechanical t t tests tton t t ulti-
Biomechanics
A. Joint Studies tt
1. General
Joint ttContracture:
Biomechanical-Clinical t t Correlates
Wayne t t H. t t Akeson
University ttof ttCalifornia
San tt Diego, ttCalifornia tt 92103
Sponsor: t t National t t Institutes tt of ttHealth
(National t t Institute t t of t t Arthritis, t t Diabetes, t t and
t t Digestive ttand ttKidney ttDiseases)
Current ttevidence ttsuggests ttthat ttstress-deprivation
tt effects tton ttsoft tttissues ttare ttprofound ttand ttoccur ttrapidly
tt and t t that t t recovery t t from t t stress t t deprivation t t is
t t quite tt slow. ttIn ttthis tt respect, tt recovery ttseems tt to
tt parallel ttthe tt effects tt of tt exercise tt on tt normal tt connective
tttissue. tt For tt example, tt our tt studies ttindicate ttthat tt a ttlarge
tt effort tt over tt a ttlong t t period t t of t t time t t is t t required
t t for t t a t t small t t hyper- tttrophy ttincrement tt of tttendons
t t or t t ligaments. t t The t t pur- tt pose tt of ttthe t t proposed
t t research t t program t t is ttto tt docu- tt ment tt further: tt (i) ttthe
ttfibrous tt connective tttissue tt mor- tt phological t t and
t t molecular t t changes t t resulting t t from tt stress
t t deprivation, t t and t t (ii) t t the t t consequent t t alteration
ttin tt physical tt characteristics. tt The tt answers ttto ttthese
tt questions t t are t t particularly t t important t t with
t t respect t t to ttthe tt development tt of ttthe tt rationale ttfor
tttreatment tt and tt rehabilitation tt of tt soft tttissue ttinjuries,
ttsuch tt as ttthe ttknee ttligaments.
A ttstandard ttinternal ttfixation ttmodel ttis ttused ttto ttinduce
ttstress-deprivation t t effects t t in t t rabbit t t knees.
t t Capsular tt and ttligamentous tt structures ttfrom ttthe tt model
tt are tt char- tt acterized tt by tt biomechanical, tt morphological,
tt biochem- ttical, tt and tt metabolic tt techniques tt on tt a
tt progressive tttime tt base t t during t t the t t development
t t of t t and t t recovery t t from ttthe tt stress-deprivation
ttstate. tt Hormone tt or tt drug tttreat- t t ment tt effects tt are tt also
tt evaluated ttfor tt efficacy ttin tt mod- tt ulating ttthe
tt development tt of tt and t t recovery ttfrom ttthe t t stress-
deprivation ttstate.
Biochemical t t analyses t t employed t t permit
t t evaluation
of ttcollagen ttturnover, tttotal ttproteoglycans, ttand ttcolla-
ttgen ttcross-link ttquantitation tt(reducible ttand
ttnonreduc- ttible). ttLight ttmicroscopy ttand tttransmission
ttEM ttare ttalso ttused ttto ttcharacterize ttmatrix ttand ttcells
104
, Rehabilitation RR&D Progress Reports 1984
tt supply. tt(ii) ttA ttflexor tttendon ttautograft ttwill t t be
mate ttstrength ttand ttstiffness ttof ttbone-ligament-bone
tt compared ttwith ttan ttallograft.
ttcomplex tt as tt well tt as ttthe tt mechanical tt properties tt of
In t t the t t first t t year, t t we t t will t t document t t the tt local
ttthe ttligament tt substance tt are tt performed. ttIn tt addition,
t t blood
tt ar- ttthrographic tt characterization tt of ttcontracture
ttstrength ttis tt assessed
Biomechanics ttof ttLigament/Tendon
ttRepairs ttand ttGrafts
Frank ttR. ttNoyes, ttM.D.
ttUniversity ttof ttCincinnati
ttCincinnati, ttOhio tt45267
Sponsor: t t National t t Institutes t t of t t Health
(National t t Institute t t of t t Arthritis, t t Diabetes, t t and
t t Digestive ttand t t Kidney t t Diseases)
It ttis ttour tthypothesis ttthat tthealing ttof ttligaments ttand
tttendons t t is t t a t t long-term t t process t t that t t involves
t t a t t return ttin t t strength t t due ttto ttcallus ttformation
ttfollowed t t by ttlong- ttterm tt remodeling tt of ttthe tt collagen,
ttinvolving tt changes ttin tt fiber tt alignment, tt ground
ttsubstance, tt and tt cross-linking. t t We t t further
t t hypothesize t t that t t the t t extent t t to t t which t t a
tt blood t t supply t t is t t available t t has t t a t t significant
t t effect t t on ttthe tt return ttin tt strength. tt Repairs ttin
ttrelatively tt vascular ttregions tt and ttfree tt grafts tt need
tt protection ttfor tt prolonged ttperiods tt of tttime. tt On ttthe
tt other tt hand, ttthe tt presence tt of tt a tt profuse t t vascular
t t supply t t may t t permit t t a t t more t t rapid tt return ttin
ttstrength, tt allowing tt earlier tt motion, tt earlier
ttrehabilitation, tt and tt return tt to tt normal tt activity tt with ttless
tt disuse tt effects.
To t t test t t these t t hypotheses, t t we t t will
t t measure t t the
return ttin ttstrength ttand ttbiochemical ttremodeling
ttover tttime ttof ttselected ttprimary ttrepairs ttand ttgrafts
ttin ttactivity ttconditioned, ttskeletally ttmature ttbeagles.
ttThe ttfollowing ttspecific ttsituations ttwill ttbe ttstudied.
Primary ttRepairs tt(i) ttWe ttwill ttcompare ttflexor-tendon
ttrepairs t t in t t highly t t vascular t t paratenon t t regions
t t with tt repairs ttin ttthe ttsynovial tt sheath, tt a
ttcomparatively tt avas- tt cular tt region. tt (ii) tt An tt anterior
ttcruciate tt mid-substance tt partial t t injury t t will t t be
t t studied t t with t t and t t without t t the t t use tt of tt a ttfat
tt pad tt sutured tt to ttthe ttligament ttto tt provide tt an
tt additional tt source tt of tt blood tt supply. tt(iii) ttHealing ttin
ttthe tt medical tt collateral ttligament tt will ttbe tt determined
ttfor tt complete tt mid-substance tttears ttinduced tt at ttthe
tttime tt of ttsurgery.
Grafts tt(i) t t A ttbone-lateral tttendon-bone ttfree ttgraft
ttsub- ttstitute ttfor ttthe ttanterior ttcruciate ttligament ttwill
ttbe ttcompared ttwith tt the ttsame ttgraft ttthat
ttincorporates tta tttissue ttflap ttthat ttprovides ttits ttblood
105
, Biomechanics
supply ttusing ttmicroangiography ttand ttrefine ttthe ttsurgi- ttgirdle ttby ttcombin- tting ttthe ttkinetics ttof ttthe ttaid ttwith
ttcal t t techniques, t t particularly t t to t t avoid
ttthe ttkinematics ttof ttthe ttupper ttlimb. ttThe ttcuffs ttof ttthe
ttelbow ttcrutches ttare ttalso ttgauged t t to t t evaluate
t t interruption t t of ttthe ttblood ttsupply. tt We tt will ttalso
t t the t t contribution t t of t t the t t cuff t t in
ttverify ttour ttexisting ttgripping ttmethods ttfor ttmechanical
tttesting ttof ttthe ttisolat- tted tttendons. ttDuring ttthe
ttsecond ttand ttthird ttyears ttof ttthe ttproject, ttwe ttwill
ttmeasure ttboth ttthe ttreturn ttin ttstrength ttand ttthe
ttbiochemical ttchanges ttin tteach ttmodel
2. Lower limb tt
Evaluation ttof ttJoint ttLoading
t tin ttthe ttUse ttof ttWalking ttAids
ttin
Total t t Hip t t Replacement t t Patients
K.A. t t Opila, t t B.Sc., t t and tt A.C. t t Nicol, t t Ph.D.
Bioengineering ttUnit
ttWolfson ttCentre
Glasgow t t G4 t t ONW, t t Scotland
Sponsor: t t University ttof ttStrathclyde
Abstract- ttThe ttimmediate ttresult ttof tttotal t t hip ttreplace-
tt ment t t surgery t t is t t a t t low-friction t t joint t t with
t t acetabular tt and t t femoral t t components t t rigidly
t t fixed t t in t t the t t pelvic ttand ttfemoral tt bones
ttrespectively. ttHowever, ttsoft tttissue tt damage t t results
t t in t t reduced t t abductor t t function t t as t t well tt as t t a
t t general t t tightness t t surrounding t t the t t hip t t joint.
Postoperative ttcare ttis tta ttcompromise; ttprotection
ttagainst ttsubluxation ttof ttthe ttjoint ttand tttearing ttof ttthe
ttabductor ttattachments ttversus ttthe ttneed ttto ttload ttthe
t t joint ttto ttreduce ttstiffness ttand ttbone ttand tttissue
ttatrophy. ttSurgeons ttvary ttin tttheir ttprescription ttof
tttherapy ttand ttwalking ttaids tt(which ttrange ttfrom
ttwalking ttframes ttto ttelbow ttcrutches ttto ttstick). ttSome
ttpatients ttare ttencour- ttaged ttto ttleave ttthe tthospital ttin
tt2 ttweeks ttwith ttno ttaids, ttwhile ttit ttis ttrecommended
ttthat ttothers ttuse ttat ttleast ttone ttstick ttup ttto tt6 ttmonths
ttpostoperatively.
The ttpurpose ttof ttthis ttstudy ttis ttto ttobtain
ttbiomechani- ttcal ttparameters ttof ttaided ttgait ttthat ttcan
ttbe ttconsidered ttwhen ttprescribing ttan ttaid ttand ttit ttuse,
ttin ttorder ttto ttoptimize tt patient ttmobility ttand ttjoint
ttprotection.
The tttypes ttof ttaids ttbeing ttstudied ttare ttelbow
ttcrutches ttand tt walking ttsticks. ttBesides ttthe tttype ttof
ttaid, ttthe tttechnique ttused ttto ttmeasure ttfor ttthe ttlength
ttof ttthe ttaid ttis ttbeing ttevaluated.
The ttanalysis ttfocuses tton ttboth ttthe ttupper ttand
ttlower ttlimbs. tt The ttshafts ttof ttthe ttaids ttare ttstrain-
gauged ttfor ttdetermination ttof ttthree ttforces. ttParticular
ttattention ttis ttgiven ttto ttthe ttloading ttof ttthe ttshoulder
106
