Proposing 6 Dimensions Within the Construct of                                 Movement in the Movement Continuum Theory  ...
Movement  Continuum Theory                                      Proposing 6 Dimensions Within the                         ...
Dimensions of Construct of Movement in the Movement Continuum TheoryT      he Movement Continuum The-          identify ap...
Dimensions of Construct of Movement in the Movement Continuum Theorydimensional model then was com-               A compar...
Dimensions of Construct of Movement in the Movement Continuum TheoryTable 1.Proposed Movement Dimensions Aligned With 4 Cr...
Dimensions of Construct of Movement in the Movement Continuum TheoryTable 2.Representative Movement Features Not Aligned W...
Dimensions of Construct of Movement in the Movement Continuum Theorydeviances and the numbers of pa-rameters (obtained fro...
Dimensions of Construct of Movement in the Movement Continuum Theory                                                      ...
Dimensions of Construct of Movement in the Movement Continuum Theorydata indicated that symmetry in re-sponses across dime...
Dimensions of Construct of Movement in the Movement Continuum Theorymovement ability. To determinewhether the magnitude of...
Dimensions of Construct of Movement in the Movement Continuum Theorylation between groups of items ordimensions to determi...
Dimensions of Construct of Movement in the Movement Continuum Theorymovement, it will have implications           odology ...
Proposing 6 Dimensions Within the Construct of                                Movement in the Movement Continuum Theory   ...
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  1. 1. Proposing 6 Dimensions Within the Construct of Movement in the Movement Continuum Theory Diane D Allen PHYS THER. 2007; 87:888-898. Originally published online May 15, 2007 doi: 10.2522/ptj.20060182The online version of this article, along with updated information and services, can befound online at: This article, along with others on similar topics, appears in the following collection(s): Kinesiology/Biomechanics Motor Control and Motor Learninge-Letters To submit an e-Letter on this article, click here or click on "Submit a response" in the right-hand menu under "Responses" in the online version of this article.E-mail alerts Sign up here to receive free e-mail alerts Downloaded from by guest on March 11, 2012
  2. 2. Movement Continuum Theory Proposing 6 Dimensions Within the Construct of Movement in the Movement Continuum Theory Diane D AllenDD Allen, PT, PhD, is Adjunct As-sociate Professor, Department ofPhysical Therapy, Samuel Merritt Background and PurposeCollege, Oakland, Calif, and Post- The Movement Continuum Theory (MCT) provides a potential basis for movementDoctoral Fellow, Health and Dis- assessment and intervention, but “movement” lacks specificity. The purposes of thisability Research Institute, Boston study were to propose and evaluate a subdivision of movement into multipleUniversity, Boston, Mass. Addressall correspondence to Dr Allen at: Subjects[Allen DD. Proposing 6 dimen-sions within the construct of A convenience sample of 318 adults completed a 24-item self-report measure ofmovement in the Movement Con- movement ability.tinuum Theory. Phys Ther.2007;87:888 – 898.] Methods© 2007 American Physical Therapy A multimethod approach was used to identify, operationalize, and test a multidimen-Association sional model of movement. Data analysis included a comparison of the fit of uni- dimensional and multidimensional models using item response theory methods and inspection of response patterns. Results A model specifying 6 dimensions—flexibility, strength, accuracy, speed, adaptability, and endurance—fit respondent data significantly better than the unidimensional model, even with high pair-wise correlations between dimensions. Response patterns showed large differences rather than uniform scores across dimensions for over half of the respondents. Discussion and Conclusion Subdividing movement into the proposed dimensions fits the data and potentially strengthens the usefulness of the MCT as a theoretical foundation for managing movement effectively. Post a Rapid Response or find The Bottom Line: www.ptjournal.org888 f Physical Therapy Volume 87 Number 7 July 2007 Downloaded from by guest on March 11, 2012
  3. 3. Dimensions of Construct of Movement in the Movement Continuum TheoryT he Movement Continuum The- identify appropriate interventions. level on the continuum) and for iden- ory (MCT),1 first published in The purposes of this study were to tifying physical, psychological, so- 1995, establishes links among propose a multidimensional model cial, and environmental factors thatmovement sciences, the movement of movement as an extension of the influence the movement,1 these as-capability of individuals, and the role MCT and to perform an initial evalu- pects of observable behavior do notof movement specialists in maximiz- ation of this new model of require redundant description. Onlying people’s movement capability. movement. the movement itself requires furtherThe MCT1 presents movement as the specification.central unifying construct for the as- Literature Reviewsessment and management of move- The MCT presents 3 general and 6 The specification of multiple subdi-ment and movement disorders in- physical therapy principles that link visions or dimensions of movementstead of the common clinical movement science with movement has support in the movement sci-practice of focusing on function or capability and clinical practice.1 In ence and clinical literature. Clinical4disability.2 Its authors proposed it as essence, movement, defined as an and motor control5 sources presenta possible grand theory of physical actual change in position, occurs at strength, flexibility, proprioception,therapy,1 but the MCT and its prin- multiple interacting levels along a and coordination as candidates forciples can enhance the understand- continuum from microscopic to the intervention following orthopedic oring of movement and potential inter- level of a person acting in society. neurologic pathology. Some of theseventions by other professions as Each level is influenced by physical, sensorimotor aspects overlap withwell. social, psychological, and environ- the list that Hedman et al6 compiled mental factors. Physical agents and as the “components of movement”Despite broad relevance and a need therapeutic exercise generally have or that Majsak7 identified as con-for theoretical foundations for clini- entry points at the tissue level or straints delineating the “range ofcal practice,1,3 the MCT has inspired higher, but because the levels inter- movement behaviors.” Additionallittle empirical research since its in- act, these interventions can affect overlap and alternative ways of spec-troduction. In a search of CINAHL molecular and cellular movement as ifying aspects of movement appearand MEDLINE databases as of August well as body part and person move- in Craik’s discussion of issues for de-2005, none of the 24 articles refer- ment. The MCT specifies that each fining normal motor behavior8 andring to the MCT since its publication person has maximum, current, and the classification that Scheets et al9contained accounts of prospective preferred movement capabilities. If a formulated for diagnosing impair-testing of the MCT or any hypothe- movement specialist successfully ad- ment of the movement system. Eachses stemming from it. dresses movement problems with a of the movement aspects and com- patient or client, then current move- ponents mentioned in these sourcesThis study initiates testing of the ment capability will increase and the could contribute to a multidimen-MCT in a direction that could ease gap between current and preferred sional model of movement.the application of this theory to em- movement capabilities will narrow.1pirical research. In this study, the Phases of Studyconstruct of movement is subdivided Testing the principles presented by This article describes 3 phases of ainto multiple components or dimen- the MCT requires an assessment of multimethod study. The purposessions that may prove more readily people’s current and preferred were to formulate and evaluate ameasurable than the singular generic movement capabilities and the effect multidimensional model of move-movement construct presented in of intervention on them. The con- ment to extend the MCT. In the iden-the MCT. A multidimensional model struct of movement as presented in tification phase, components ofsuch as the model proposed here the MCT, however, is too generic for movement from the literature weremay stimulate both the generation of clinical assessment. Specifying subdi- evaluated on the basis of a set oftestable hypotheses and the associa- visions or dimensions of movement criteria for inclusion into an econom-tion of current evidence of effective- may assist in identifying clinically ical model. In the operation phase,ness with a unified theory. A multi- measurable constructs that have a the set of dimensions and the MCTdimensional model of movement definitive relationship to the move- formed the basis of a new measurealso may promote the characteriza- ment capabilities presented in the constructed to incorporate both ge-tion of people’s different movement MCT. Because the MCT already pre- neric and multidimensional con-abilities, enhancing the specificity sents a framework for identifying structs of movement. In the testwith which clients and movement what part of the person moves (eg, phase, data were collected with thespecialists can pinpoint deficits and at the tissue, body part, or person new measure. The proposed multi-July 2007 Volume 87 Number 7 Physical Therapy f 889 Downloaded from by guest on March 11, 2012
  4. 4. Dimensions of Construct of Movement in the Movement Continuum Theorydimensional model then was com- A comparison of possible movement Operation Phase:pared with a unidimensional model dimensions with the criteria led to Method and Resultsof movement and with a multidimen- the addition, modification, or elimi- The next step in determining thesional model with randomly attrib- nation of candidates. Tables 1 and 2 usefulness of this set of dimensionsuted dimensions. Because the phases show comparisons of the first 4 cri- was to construct or locate measuresnecessarily occurred sequentially, teria with the proposed (Tab. 1) and for assessing movement. If the samethe results follow the method for some of the rejected (Tab. 2) candi- measure could evaluate both genericeach phase in sequence. dates for movement dimensions. The and multidimensional movements, fifth criterion implies that people then it would facilitate the directIdentification Phase: can differentiate among and use the comparison of a generic or overallMethod and Results various dimensions in their observa- idea of movement with the dimen-Generating the set of potential move- tions and descriptions of movement. sions of movement proposed in thement dimensions consisted of setting Testing this implication or otherwise model. In addition, because the MCTevaluative criteria, identifying from providing evidence of understanding and the proposed model apply to aliterature sources common features of any of the movement dimensions broad range of ability levels and toof movement to propose as candi- will require empirical data. the movements of people with ordates, and comparing those candi- without pathologic conditions, thedates with the criteria to ensure The resulting set of dimensions in- ideal measure for comparing genericalignment. The criteria for potential cludes flexibility, strength (force ex- and multidimensional constructsdimensions of movement to extend erted), accuracy, speed, adaptability, would apply to a similar range. Manythe MCT included the following: and endurance. These 6 dimensions measures of movement exist for test- describe observed movement com- ing individual dimensions, specific(1) Descriptive: The complete set of prehensively and efficiently (criteria diagnostic groups, or particular body dimensions, with an added refer- 1 and 2). The proposed dimensions parts exist, but few existing mea- ence to the body parts or sub- of flexibility, strength, and speed ap- sures assess generic movement abil- stances doing the moving, ply to all human movement; accu- ity or apply to multiple groups or should fully describe normal hu- racy applies specifically to purpose- across the proposed dimensions. man movement, a series of ful movement; and adaptability and movements, or actively holding endurance apply to movement when Generation of the self-report Move- a position against a force. encountering unexpected obstacles ment Ability Measure (MAM) opera- or when approaching the limits of a tionalized the MCT and the proposed(2) Efficient: The set of dimensions person’s capacity. All of these dimen- model and facilitated direct compar- should describe movement effi- sions have direct relationships with ison of unidimensional and multi- ciently, subsuming related con- but remain distinct from the physi- dimensional models of movement. cepts, with the fewest number cal, psychological, social, and envi- For addressing a generic or uni- of separate dimensions while ronmental factors that influence dimensional construct of movement, completely describing movement. movement (criterion 3). Each candi- all items in the MAM were given a date dimension can be measured similar item construction and stan-(3) Distinct: The dimensions should clinically (criterion 4). Although fur- dard levels of item responses. If peo- identify observable features of ther research may justify modifica- ple marked every item with the same movement distinct from the part tion of this set, these 6 dimensions level of response, then a generic of the body doing the moving or provide a starting point for charac- movement construct could specify different physical, psychologi- terizing movements readily observed their movement ability quite ade- cal, social, or environmental fac- by movement specialists and their quately. For addressing a multi- tors that influence movement. patients or clients (toward criterion dimensional construct of movement, 5). In addition, these 6 dimensions variations in the wording of items in(4) Measurable: The dimensions present interesting possibilities for the MAM referred specifically to the should be measurable. categorizing movement abilities 6 proposed dimensions of move- maximized by athletes or performing ment. If people marked items associ-(5) Understandable: The dimensions artists or diminished in people with ated with one dimension quite differ- should make sense to both a particular pathologic condition ently from items associated with movement specialists and their (Tab. 3). other dimensions, then specification patients or clients. of their ability on that dimension890 f Physical Therapy Volume 87 Number 7 July 2007 Downloaded from by guest on March 11, 2012
  5. 5. Dimensions of Construct of Movement in the Movement Continuum TheoryTable 1.Proposed Movement Dimensions Aligned With 4 Criteria Dimension Descriptive (eg, Efficient (Summarizes Distinct (Requires, But Measurable (Can Be Ascending and Subsumes These Is Distinct From, Each of Assessed With These Stairs) Related Concepts) These Physical Factors) Clinical Measures, Among Others) Flexibility4 Extent and ease of Extent of linear or angular Appropriate muscle stiffness, Range of motion (goniometer movement at displacement, range of muscle tone,6,7 and or electrical potentiometer) joints to reach motion,8,9 amplitude, muscle length7; joint and and extent of movement next step ease of movement, and ligament integrity; and (video or optoelectric mobility6 skin and connective tissue systems) integrity Strength4 Force to propel or Force behind Appropriate number, size, Myometry, manual muscle withstand displacement, force and type of muscle fibers; testing, force transducer, against forces to generation,6,8 and muscle integrity and and electromyographic lift mass tension generation recruitment7; and neural amplitude (relative to integrity maximum) Accuracy Attainment of Direction and timing of Cerebellar integrity and Distance between result of target position displacement, neuromuscular integrity movement and target; error on each coordination,6,7,9 timing scores; distance or number subsequent step and sequencing,7,9 of deviations from target fractionating or trajectory; and synchrony isolating movement,9 with a timing target, and selective capacity6 cadence, and electromyographic timing Speed6,8,9 Velocity of ascent Speed of displacement Neuromuscular integrity and Distance divided by time and of steps and velocity biomechanical integrity cinematography Adaptability Change when Adjustment during Sensory integrity, reflexes,7 Sensory integration tests and unexpected displacement, and integrity of reaction times following step height or adaptation to sensorimotor cortical areas encounter of unexpected texture is environmental and pathways stimuli encountered changes,5 adaptive capacity,6 and sensorimotor interaction7 Endurance6–8 Persistence of Continuation through Cardiopulmonary health and Duration plus extent of ascent up all completion of vascular integrity movement, perceived steps without displacement, exertion, and change in flagging persistence, and cardiopulmonary measures perseverance or vital signscould enhance the description of The MAM was developed and tested would like to be able to move. Threetheir movement ability. for reliability and for content and sample items and instructions are construct validity with procedures shown in Figure 1. The MAM in-The self-report format allowed sub- recommended by Wilson10; evi- cluded 4 items for each of the 6 di-jects to interpret movement as a dence of reliability and validity is pre- mensions, for a total of 24 items. Thewhole or differentiate movement di- sented elsewhere (see the article by same instructions applied to allmensions within the context of their Allen on the validity and reliability of items. Consistency of responsesown lives. The MAM placed minimal the Movement Ability Measure in across items was high, with personconstraints on subject interpreta- this Special Series).11 Each item in separation reliability ranging fromtion. In avoiding the specification of the MAM consisted of 6 statements .92 to .96 for the 6 dimensions andtasks that may have limited relevance indicating levels of movement abil- equaling .98 for the whole measure.across groups, the MAM also applied ity. Respondents were instructed toto a broad range of subjects across choose the statement that most Test Phase: Methodmovement ability levels and with or closely matched how they thought For the test phase, a heterogeneouswithout pathologic conditions. they moved now and how they sample of people completed theJuly 2007 Volume 87 Number 7 Physical Therapy f 891 Downloaded from by guest on March 11, 2012
  6. 6. Dimensions of Construct of Movement in the Movement Continuum TheoryTable 2.Representative Movement Features Not Aligned With Criteria Feature of Movement Unmet Criteria Posture6,7 Efficient and distinct: posture, when active, as during holding of a position against a force such as gravity, can be described adequately with a combination of other dimensions; when passive, it influences but does not describe subsequent movement Balance6 Efficient: balance is a complex set of sensorimotor activities that can be described with a combination of the proposed dimensions, such as adaptability, strength, and flexibility Cognitive capacity,6 psychological capacity,6 ability to learn,9 Distinct and descriptive: these psychological factors influence and motivation and alertness7 movement and the intention behind movement but do not describe movement itself Pain6 Distinct and descriptive: pain, perhaps a physical or psychological factor influencing movement, does not describe movement itself Alignment, center of mass, and base of support7 Distinct and descriptive: these physical (biomechanical) factors influence movement but do not describe movement itself Proprioception,4 sensory modalities,9 perception of vertical,9 Distinct and descriptive: sensation and perception are physical perception of motion,9 and sensory information6 and psychological factors that influence the ability to learn movement or to adapt to an environment but do not describe movement itselfMAM. The expectation was that multidimensional model would fit tain a heterogeneous representationmost people who move normally the data better than a unidimensional of movement abilities. Adults volun-might perceive themselves to have model. The proposed multidimen- teered from religious and commu-about the same level of movement sional model was compared with a nity groups, personal contacts, a col-ability on all 6 dimensions; therefore, unidimensional model and with a lege sports team, physical therapya unidimensional model would fit multidimensional model in which outpatient clinics, and a senior daythe data very well. If people perceive items were randomly assigned to activity event. In addition to thedifferences in the effects of different dimensions. MAM, respondents completed adimensions on their movement abil- cover sheet of information aboutity, then they might respond quite Recruitment of volunteers to re- health status and any movementdifferently to items associated with spond to the MAM targeted a broad problems. Respondents were in-those dimensions. In this situation, a spectrum of groups in order to ob- formed that completing and return- ing the questionnaire constituted consent for their (anonymous) re-Table 3. sponses to be included in the study.Proposed Dimensions and Sample Activities or Pathologies Relevant to Each Dimension Sport or Activity Pathology The data were analyzed with item Flexibility Gymnastics, ballet Arthritis, Parkinson disease response theory (IRT) methods12 and ConQuest13,* software, and only Strength Weight lifting, moving furniture Muscular dystrophy, stroke, peripheral nerve injury the “now” responses to items were analyzed. Two models were com- Accuracy Archery, tap dancing Cerebellar disease pared. One model assigned all items Speed Sprinting, piano playing Parkinson disease, other diseases of to 1 dimension in a unidimensional the basal ganglia, loss of fast-twitch construct; the other assigned items muscle fibers to the 6 dimensions in a multidimen- Adaptability Skiing, tennis, juggling, reactive Sensory or perceptual loss from sional construct. Fit was analyzed on balance auditory, visual, vestibular, or the basis of the differences in the somatosensory systems Endurance Running a marathon, singing an Cardiovascular or pulmonary diseases * Australian Council for Educational Research, opera Hawthorn, Victoria, Australia.892 f Physical Therapy Volume 87 Number 7 July 2007 Downloaded from by guest on March 11, 2012
  7. 7. Dimensions of Construct of Movement in the Movement Continuum Theorydeviances and the numbers of pa-rameters (obtained from ConQuest)by use of the G2 likelihood ratio sta-tistic. For a more complex (multidi-mensional) model to fit better thana simpler nested (unidimensional)model, it must result in a lower de-viance (a measure of lack of fit of thedata to the model) than can be ac-counted for simply by the greaternumber of parameters estimated.The difference between the devi-ances for the 2 models functions likea chi-square distribution with the dif-ference in the number of parametersas the degrees of freedom. Correla-tions also were obtained for each pairof dimensions in the multidimensionalmodel.To assess whether any multidimen-sional model would fit better thanthe unidimensional model for thesedata, a random multidimensionalmodel was generated, with items as-signed randomly, but without repli-cation, to generic dimensions. Thatis, no more than one item from anyproposed dimension was allowedper generic dimension. This randommultidimensional model also wascompared with the unidimensional Figure 1.model with the G2 likelihood ratio Example of 3 Movement Ability Measure items directed toward the dimensions ofstatistic as described previously. flexibility, speed, and strength. Respondents were instructed to choose the one state- ment within each box that most closely described their usual ability to move now, thisIn addition to the comparisons of week, and the one statement that most closely described the ability that they would likemodels with the G2 statistic, the pat- to have even if they had to work hard for it. They were instructed to mark one number on the left (Now) and one number on the right (Would Like) for each set of 6terns of responses of individual re- statements.spondents were examined. Examin-ing uniform or uneven patterns ofresponses across dimensions mightprovide insight into the constructs in dimensions (d) for each person p, as movement ability on at least one ofthe proposed model. A sum of follows: the dimensions to be quite differentsquares indicator, DI, was calculated from the average of the rest. Repre- sentative respondents with low and ͸ ͓͑␪៮ Ϫ ␪ ͒ ͔to indicate the sizes of the differ- 6ences in responses across dimen- DI p ϭ d 2 high DI values were selected; move-sions.14 For this calculation, move- dϭ1 ment ability plots (MAPs) depictedment levels and respondent abilities the asymmetry of dimensions for(␪) were examined in logits, the log If the sum of the squared deviations these selected respondents with lowof the odds of choosing the state- from an average estimate is low, then and high DI values. Designation ofment indicating a given level of that person perceives his or her low and high DI values within anymovement ability within each item. movement to be about the same particular study is arbitrary.15 ForThe DI sums differences from move- across all 6 dimensions. If DIp is this study, the lowest and highestment ability estimates across the 6 high, then that person perceives average logits for any dimensionJuly 2007 Volume 87 Number 7 Physical Therapy f 893 Downloaded from by guest on March 11, 2012
  8. 8. Dimensions of Construct of Movement in the Movement Continuum Theory side of their respective 98% confi- dence intervals (standard errors for average dimension estimates were about 1 logit), and the spread signi- fied at least 0.5 and up to 1.25 move- ment ability level differences be- tween the dimensions. At a DI value of 5.3, 165 (52%) of the respondents showed differences between the di- -6 mensions of movement rather than a uniform average across dimensions. -11 Movement ability plots of sample cases (Figs. 2, 3, 4, 5, 6, and 7) cho- sen to represent low and high DI values depict dimensional abilities in logits along 6 respective axes in a hexagon (range for all axesϭϪ11 to ϩ9 logits). Greater asymmetry indi- cates larger differences between di- mensions. Demographic information is provided when known from re- sponses and comments on com- pleted questionnaires.Figure 2.Respondent 201 reported low movement ability (low logit values) on all dimensions. Discussion and ConclusionThis respondent was an 86-year-old woman who reported that she was “clumsy” and The 3 phases of this study resulted inhad low back problems. The sum of the squared deviations from an average dimen- a proposed set of dimensions to ex-sional logit value, DI201ϭ0.47 logit2. tend the construct of movement within the MCT. The proposed di- mensions included aspects of move-were inspected for each respondent; tidimensional model fit significantly ment that were described in the lit-the DI cutoff was assigned to the better than the unidimensional erature and that were aligned withvalue above which all respondents model (␹225ϭ280.9, PϽ.0001), even evaluative criteria. Testing the pro-had differences from their lowest to with high internal consistency across posed dimensions required the con-their highest dimensions that were all items (Cronbach ␣ϭ.94) and high struction of a new measure targetinglarge enough to be outside of a 98% correlations between pairs of dimen- these movement constructs alongconfidence interval. tions (rϭ.87–.99). In contrast, when with a generic movement construct. items were randomly assigned to 6 Model comparisons carried out withTest Phase: Results generic dimensions, the multidimen- data obtained with the new measureA total of 318 adults completed the sional model fit no differently than showed that the proposed multidi-MAM. Respondent ages ranged from the unidimensional model (␹225ϭ mensional model fit better than a18 to 101 years, with modes (10 23.3, Pϭ.56). unidimensional model.each) at ages 49 and 76. Women con-stituted 206 (65%) of the respon- When response patterns were exam- Despite the dimension-specificdents; 178 (56%) acknowledged at ined with the DI statistic (meanϭ wording of the MAM, many respon-least a little movement difficulty in 9.25 logits2, standard deviationϭ dents provided no discernible indica-the previous week. Forty-six respon- 11.62), 5.3 logits2 was designated as tion that their movement was differ-dents (14%) indicated that they were the cutoff between low and high. No ent across dimensions. For them,starting or undergoing physical ther- person who had a DI value above responses across the dimensions in-apy at the time of responding to the this cutoff had less than 2.5 logits dicated about the same level ofMAM. between the lowest and the highest movement ability, although that average dimension estimates. At 2.5 movement ability might have beenWith items specifically assigned to 6 logits, the lowest and highest aver- low or high, as shown in Figures 2corresponding dimensions, the mul- age dimension estimates were out- and 3. The associated demographic894 f Physical Therapy Volume 87 Number 7 July 2007 Downloaded from by guest on March 11, 2012
  9. 9. Dimensions of Construct of Movement in the Movement Continuum Theorydata indicated that symmetry in re-sponses across dimensions mighthave been associated with debilita-tion or physical capability in general. 4For more than half of the respon- -1dents in this study, MAM responseswere different across dimensions.Some respondents showed excep- -6tionally low levels of ability on somedimensions (Figs. 5 and 7), andothers showed exceptionally high -11levels of ability on 1 or 2 dimensions(Fig. 6). These responses imply suf-ficient understanding of the dimen-sions in the MAM to reflect con-sistent differences (with personseparation reliability ranging from.92 to .96) across designated groupsof items. This is initial evidence thatthis set of dimensions may meet cri-terion 5. Determining whether suchdifferences across dimensions haveclinical meaning depends on future Figure 3.research. Comparing the demo- Respondent 244 reported high movement ability on all dimensions. This respondentgraphic data to the MAPs suggested a was a 72-year-old man who was healthy. The sum of the squared deviations from anlink between responses and respon- average dimensional logit value, DI244ϭ3.15 logits2.dent characteristics rather than ei-ther uniform or random responses toitems. 4Although these results provide someinitial evidence supporting the sub- -1division of the movement constructof the MCT into the 6 proposed di-mensions, validation of the proposed -6model requires further research. Forexample, the MAM deliberately al- -11lowed respondents to interpretitems without specifying standardtasks; this property increased its ap-plicability across individuals with dif-ferent experiences of functional ac-tivities but restricted the absolutecomparison of one individual withanother or of MAM responses withinstrumented measures. To deter-mine whether differences in per-ceived movement ability correlatewith measurable differences in di- Figure 4.mensions, future research might ex- Respondent 39 reported higher movement ability on flexibility, strength, and endur-amine the association between MAM ance and lower movement ability on accuracy, speed, and adaptability. This respondentresponses and performance-based was a 65-year-old man. The sum of the squared deviations from an average dimensionalmeasures or clinicians’ judgments of logit value, DI39ϭ28.22 logits2.July 2007 Volume 87 Number 7 Physical Therapy f 895 Downloaded from by guest on March 11, 2012
  10. 10. Dimensions of Construct of Movement in the Movement Continuum Theorymovement ability. To determinewhether the magnitude of perceivedmovement ability has meaning, fu-ture research might examine groupdata for each dimension and com-pare healthy control subjects withsubjects who have identified defi-ciencies. To explore the possibleclinical meaning of the proposed di-mensionality, future research mightexamine people before and after -11therapy to determine whether thosewho respond well to therapy startedwith a generic lack of movementability across all dimensions or a spe-cific and predictable lack of move-ment ability in one dimension or afew dimensions. Further researchalso might indicate that MAPs revealidentifiable patterns of asymmetryfor certain clinical groups.Asymmetry across different dimen- Figure 5.sions should follow predictable pat- Respondent 186 reported moderate movement ability on adaptability and much lowerterns according to the proposed mul- movement ability on the other dimensions, especially flexibility. This respondent was a 76-year-old woman who had had a stroke. The sum of the squared deviations from antidimensional model of movement. average dimensional logit value, DI186ϭ68.34 logits2.For example, athletes should testhigher in predictable subsets ofthese dimensions, depending on therequirements of their specific sport-ing events, as proposed in Table 3.Likewise, patients should test lowerin predictable ways if they have di-agnoses affecting 1 or several desig- -1nated dimensions. Furthermore, ifthese dimensions extend the MCT, -6then patients should improve in af-fected dimensions upon successfulcompletion of a clinical intervention. -11If research confirms predictable pat-terns among the dimensions relatedto athletic ability or pathology-related disability, then characteriza-tion of movement ability along thedimensions may prove useful in de-termining prognosis and planningfor client intervention.A common alternative statisticalmethod for determining dimension- Figure 6.ality, factor analysis, proved unhelp- Respondent 316 reported higher movement ability on endurance and moderate move-ful in this study. Exploratory or con- ment ability on the other dimensions. This respondent was a 25-year-old woman whofirmatory factor analysis of an was a long-distance runner. The sum of the squared deviations from an averageinstrument relies on a lack of corre- dimensional logit value, DI316ϭ29.35 logits2.896 f Physical Therapy Volume 87 Number 7 July 2007 Downloaded from by guest on March 11, 2012
  11. 11. Dimensions of Construct of Movement in the Movement Continuum Theorylation between groups of items ordimensions to determine whetherdifferent factors are represented. Forperceived movement ability as as-sessed with the MAM, the dimen-sions had an extremely high pair-wise correlation that negatedconfirmation of factors with factoranalysis. Choosing IRT methods totest dimensionality proved more use-ful in this study because these meth- -11ods estimate item and respondent lo-cations on the same (logit) scale onthe basis of all of the recorded re-sponses to all of the items. Thus, IRTmethods retain the distinctions be-tween items and groups of itemsmade by individual respondentsrather than subsuming all of thosedifferences in pooled correlationdata across a sample.Although the MCT describes move- Figure 7.ment at all levels, from the molecular Respondent 309 reported low movement ability on flexibility and strength and mod-and cellular levels to the level of a erate movement ability on the other dimensions. This respondent was a 40-year-oldperson acting in society, the MAM man with limited neck and arm function because of impingement. The sum of the squared deviations from an average dimensional logit value, DI309ϭ123.02 logits2.incorporates the 6 dimensions ofreadily perceivable movement only.Further research is needed to deter-mine whether these 6 dimensions study will promote discussion of potheses, however, the MCT willapply to the molecular and cellular movement and all of its possible fail to provide a foundation for as-levels of the continuum described by dimensions. sessment and intervention. The pro-the MCT or whether separate move- posed multidimensional model mayment descriptors are more applica- The subjects in this study were not a promote hypothesis generation be-ble for these levels. randomized sample; subjects who cause the specificity of the dimen- volunteered to complete the self- sions makes measuring movementAlthough numerous discussions with report measure may have self- with the MCT more concrete.professional informants helped re- selected either because they thought Strength, for example, as a dimen-fine the set of dimensions described they moved well or because they sion within the movement con-here and although these dimensions were conscious of movement prob- struct of the MCT, has links amongmet the evaluative criteria, the liter- lems. Neither of these motivations the assessment of strength in theature search for movement dimen- was thought to bias the results par- laboratory, the problems of weak-sion candidates was neither exhaus- ticularly, as this study focused on di- ness, and the intervention used totive nor systematic. Further research mensionality and not the level of improve current ability to gener-may provide support for the exclu- movement ability. ate force. Characterizing movementsivity of these dimensions or provide capabilities across dimensions andsome other criteria for accepting dif- An alternative to the disablement testing any narrowing of the gap be-ferent dimension candidates. Re- models described as the basis of tween current and preferred move-search also may modify the concepts the Guide to Physical Therapist ment capabilities as a result of inter-of these dimensions, splitting some Practice,2 the MCT1 presents a po- vention become possible.into smaller subdivisions or merging tential grand theory of physicalothers on the basis of some alterna- therapy3 that also could be relevant If the research suggested in this dis-tive criteria. It is hoped that the iden- to movement specialists in other cussion further supports the MCTtification of the 6 dimensions in this professions. Without testable hy- and the proposed dimensions ofJuly 2007 Volume 87 Number 7 Physical Therapy f 897 Downloaded from by guest on March 11, 2012
  12. 12. Dimensions of Construct of Movement in the Movement Continuum Theorymovement, it will have implications odology of testing. The author also thanks 7 Majsak MJ. Consolidating principles of mo- Rick Allen for support and editing advice tor learning with neurologic treatmentaffecting research, education, and techniques in a professional physical ther- throughout the process of conceptualizing,clinical practice. In research, the apist program. Neurology Report. 1996; testing, and writing. 20:19 –27.MCT and dimensions of movement A version of this study was presented as a 8 Craik RL. Abnormalities of motor behav-could provide a framework for re- ior. In: Lister MJ, ed. Contemporary Man- poster at the Combined Sections Meeting ofvealing relationships among flexibil- agement of Motor Control Problems: Pro- the American Physical Therapy Association; ceedings of the II-Step Conference.ity, strength, and speed, for exam- February 1–5, 2006; San Diego, Calif. This Alexandria, Va: Foundation for Physicalple, providing a needed unification study was completed as part of the author’s Therapy; 1991:155–164.for effectiveness evidence. In educa- doctoral dissertation at the University of Cal- 9 Scheets PK, Sahrmann SA, Norton BJ. Di- ifornia, Berkeley. agnosis for physical therapy for patientstion, a focus on movement dimen- with neuromuscular conditions. Neurol-sions provides a natural link between The Committee for the Protection of Human ogy Report. 1999;23:158 –169.basic and movement sciences and Subjects at the University of California, 10 Wilson M. Constructing Measures: An Berkeley, designated this study exempt from Item Response Modeling Approach. Mah-the movement deficits associated wah, NJ: Erlbaum; 2005. further review.with particular pathologic condi- 11 Allen DD. Validity, Reliability, and Re-tions, perhaps improving student This article was received June 27, 2006, and sponsiveness of the Movement Ability was accepted March 1, 2007. Measure, a New Instrument Proposed forunderstanding of assessment and in- Assessing Physical Therapist Competencetervention relationships across diag- DOI: 10.2522/ptj.20060182 [dissertation]. Berkeley, Calif: Graduate School of Education, University of Califor-nostic groups. In clinical practice, nia; 2005.the dimensions of movement may References 12 Adams RJ, Wilson M, Wang W. The multi-help patients and movement special- 1 Cott CA, Finch E, Gasner D, et al. The dimensional random coefficients multino- mial logit model. Applied Psychologicalists more readily specify and focus movement continuum theory of physical Measurement. 1997;21:1–23. therapy. Physiother Can. 1995;47:87–95.assessment and intervention on the 13 ACER ConQuest: Generalised Item Re- 2 Guide to Physical Therapist Practice. 2nddimensions having the most diffi- ed. Phys Ther. 2001;81:9 –746. sponse Modelling Software [computer program]. Version 2.0. Hawthorn, Victo-culty. Across all areas, dissemination 3 O’Hearn MA. The elemental identity of ria, Australia: ACER (Australian Council forand use of the MCT and dimensions physical therapy. Journal of Physical Educational Research) Press; 2003. Therapy Education. 2002;16:4 –7.of movement could enhance effec- 14 Briggs DC, Wilson M. An introduction to 4 Tomberlin JP, Saunders HD. Evaluation, multidimensional measurement using Ra-tiveness in investigating and manag- Treatment and Prevention of Musculo- sch models. Journal of Applied Measure-ing movement. Although this study skeletal Disorders. Vol 2. 3rd ed. Chaska, ment. 2003;4:87–100. Minn: The Saunders Group; 1994.addressed only the initial testing 15 Allen DD, Wilson M. Introducing multidi- 5 Shumway-Cook A, Woollacott MH. Motor mensional item response modeling inof the proposed multidimensional Control: Theory and Practical Applica- health behavior and health education re-model of movement and the MCT, tions. 2nd ed. Philadelphia, Pa: Lippincott search. Health Educ Res. 2006;21(suppl Williams & Wilkins; 2001. 1):i73–i84.the potential usefulness of this 6 Hedman LD, Rogers MW, Hanke TA. Neu-theory makes further research rologic professional education: linking theworthwhile. foundation science of motor control with physical therapy interventions for move- ment dysfunction. Neurology Report. 1996;20:9 –13.The author acknowledges Mark Wilson forsparking the original idea of dimensions ofmovement and for his direction in the meth-898 f Physical Therapy Volume 87 Number 7 July 2007 Downloaded from by guest on March 11, 2012
  13. 13. Proposing 6 Dimensions Within the Construct of Movement in the Movement Continuum Theory Diane D Allen PHYS THER. 2007; 87:888-898. Originally published online May 15, 2007 doi: 10.2522/ptj.20060182References This article cites 9 articles, 1 of which you can access for free at: by This article has been cited by 3 HighWire-hosted articles: and Reprints for Authors Downloaded from by guest on March 11, 2012