Development of the Comprehensive Observations of Proprioception (COP): Validity, Reliability, and Factor Analysis Erna Imperatore Blanche, Stefanie Bodison, Megan C. Chang, Gustavo Reinoso KEY WORDS developmental disabilities observation proprioception sensory motor performance somatosensory disorders Erna Imperatore Blanche, PhD, OTR/L, FAOTA, is Associate Professor, Division of Occupational Science and Occupational Therapy, University of Southern California, 1540 Alcazar, CHP–133, Los Angeles, CA 90089; firstname.lastname@example.org Stefanie Bodison, OTD, OTR/L, is Postdoctoral Fellow, Division of Occupational Science and Occupational Therapy, University of Southern California, Los Angeles. Megan C. Chang, PhD, OTR/L, is Assistant Professor, Department of Occupational Therapy, San Jose´ State University, San Jose´, CA. Gustavo Reinoso, PhD, OTR/L, is Director, Advance Therapy Systems, Dundalk, County Louth, Republic of Ireland. OBJECTIVE.
We developed an observational tool, the Comprehensive Observations of Proprioception (COP), for identifying proprioceptive processing issues in children with developmental disabilities. METHOD. Development of the COP underwent three phases. First, we developed items representing proprioceptive functions on the basis of an extensive literature review and consultation with occupational therapists. We then established interrater reliability and content, construct, and criterion validity. Finally, we completed a factor analysis of COP ratings of 130 children with known developmental disabilities. RESULTS. Adequate validity and reliability were established. Factor analysis revealed a four-factor model that explained the underlying structure of the measure as it was hypothesized. CONCLUSION. The COP is a valid criterion-referenced short observational tool that structures the clinician’s observations by linking a child’s behaviors to areas identified in the literature as relevant to proprioceptive processing. It takes 15 min to administer and can be used in a variety of contexts, such as the home, clinic, and school. Blanche, E. I., Bodison, S., Chang, M. C., & Reinoso, G. (2012). Development of the Comprehensive Observations of Proprioception (COP): Validity, reliability, and factor analysis. American Journal of Occupational Therapy, 66, 691–698.
http://dx.doi.org/10.5014/ajot.2012.003608 Proprioception, defined as the sum of neuronal inputs from the joint capsules, ligaments, muscles, tendons, and skin, is a multifaceted system that influences behavior regulation and motor control (Ashton-Miller, Wojtys, Huston, & Fry-Welch, 2001; Ayres, 1972, 1989; Coleman, Piek, & Livesey, 2001; Ferrell et al., 2004; Grob, Kuster, Higgins, Lloyd, & Yata, 2002; Laszlo & Sainsbury, 1993; Lephart & Fu, 2000). Children with developmental disabilities often exhibit difficulties in processing proprioceptive information; however, few systematic evaluation tools are available that identify proprioceptive dysfunctions and help clinicians design precise intervention strategies to address them. The objectives of the study described in this article were to develop a new observational tool to identify proprioceptive processing disorders in children with developmental disabilities and to establish its validity and reliability.
She differentiated proprioception from kinesthesia and considered the former to be unconscious information from muscles and related structures and the latter to be conscious awareness of joint position and movement (Ayres, 1972, p. 67), a differentiation that is no longer made. Later writers added to the description of proprioception: Fisher (1991) described proprioception as being linked to vestibular processing disorders and feed-forward mechanisms, Dunn (1999) linked proprioception to sensory-seeking behaviors, and Blanche and Schaaf (2001) linked proprioception to both tactile and vestibular processing disorders and to motor-planning and sensory-seeking behaviors. Clinicians presently use three methods to collect information about proprioception: (1) the Kinesthesia (KIN) and Standing and Walking Balance (SWB) tests of the Sensory Integration and Praxis Tests (SIPT; Ayres, 1989); (2) parent report of behaviors theoretically linked to proprioceptive functions, such as the Sensory Profile (SP; Dunn, 1999) and the Sensory Processing Measure Home Form (SPM–Home Form; Parham & Ecker, 2007); and (3) unstructured observations of the child’s behaviors (Blanche, 2002, 2006; Blanche & Reinoso, 2008). These tools present several problems, however.
The KIN test provides a standardized measure of only one aspect of proprioceptive abilities, and the SWB test is a measure of proprioceptive and vestibular abilities and therefore is not a pure measure of proprioception; the SP and SPM–Home Form depend on a parent’s or teacher’s perception of abilities that relate to proprioceptive processing; and the unstructured observations rely on the clinician’s understanding of proprioception. The results obtained from these methods of gathering information do not always correspond because they measure the impact of proprioception on two different areas of performance: motor performance and regulation of behavior. The tool described in this article organizes the clinician’s observations by providing a structured way to measure the relationship of proprioception to motor performance and to arousal modulation; this tool is intended to accompany other forms of gathering information such as those listed previously. Method The Comprehensive Observations of Proprioception (COP) is a criterion-based observational tool we originally constructed to measure two main areas of proprioceptive functions: behavior and sensory–motor abilities. The tool also includes two items described in the literature as related to proprioception: muscle tone and hypermobility (Ferrell et al., 2004). The COP is an observational tool that takes 15 min to administer while the clinician observes the child during free play. We collected data from existing charts in two clinics in the Los Angeles area after obtaining approval from the University of Southern California institutional review board (IRB).
Other motor abilities linked to proprioception include motor programming, postural control, fluidity of movement, calibration of spatial frame of reference, feedback from outcome of motor commands, joint stability, conscious estimation of muscle force, and orientation of body segments or body scheme (Bard et al., 1995; Ferrell et al., 2004; Gandevia et al., 2002; LaRue et al., 1995; Laszlo & Bairstow, 1980). We included items representing each of these areas of performance in the COP (Table 1). Phase 2: Establishment of Validity and Reliability We established face and content validity following the recommendations outlined by Goldsmith (1993) and Portney and Watkins (2009). A panel of nine occupational therapists who were experts in sensory integration rated each item of the pilot version of the questionnaire as 11 5 item is a definite measure of proprioception, 0 5 undecided as to whether the item is a measure of proprioception, and 21 5 item is not a measure of proprioception. On the basis of the expert review, we modified the scale, retaining items identified as strong (index ³ .70) or adequate (.60 < index £ .69). The expert panel also identified five items in the structured clinical observations that they considered to be related to proprioceptive processing: (1) arms come down during Schilder’s arm extension test (Schilder, 1931; Silver & Hagin, 1960), (2) lack of fluidity or inability to maintain pace during slow ramp movements, (3) finger does not reach tip of nose during finger-to-nose task, (4) poor performance in the sequential finger-touching test, and (5) poor performance during alternating movements. The experts rejected four items they did not consider to be related to proprioception: (1) feedback-related motor-planning skills are inappropriate for age, (2) feed forward–related motorplanning skills are inappropriate for age, (3) child is overactive, and (4) child is passive.
We established construct validity by reviewing the charts of 24 children (7 girls, 17 boys) with known problems (P group) and comparing their performance on the COP with the performance of 20 children without proprioceptive difficulties (NP group) matched by age (mean 5 6 yr, 7 mo; range 5 2 yr to 8 yr, 11 mo). One of the primary investigators of this study (Bodison) rated the children without proprioceptive difficulties using the COP during play activities in a public setting, as specified by IRB procedures. We established criterion validity by comparing the P group’s results on the Body Awareness (BOD) section of the SPM–Home Form (Parham & Ecker, 2007) and the KIN and SWB subtests of the SIPT (Ayres, 1989) with their performance on the COP. The SIPT and the SPM– Home Form are commonly used in pediatric practice to evaluate the sensory functions of children.
The SIPT is a norm-referenced standardized assessment occupational therapists use to determine the underlying sensory processing problems that might be affecting a child’s occupational performance. The SPM–Home Form is a parent-completed questionnaire that allows caregivers to communicate their observations of the child’s difficulties in everyday tasks; the Body Awareness items included in our analysis are presented in Table 2. We analyzed the chart review results using Pearson’s bivariate correlations to explore whether the COP was measuring proprioceptive functions as accurately as the two measures of proprioception commonly used in pediatric practice. Phase 3: Factor Analysis To aid in the process of ongoing construct validation (Portney & Watkins, 2009), we conducted an exploratory factor analysis (EFA) with oblique rotation. We collected data from 130 children with a diagnosis of developmental delay ages 2–9 yr. We hypothesized that the underlying structure of the variables would reflect the dimension of the scale—that is, tone and mobility, motor skills, and behavioral manifestations.
Table 3 displays the results from the EFA. Results Construct Validity The children with developmental disabilities (P group) had significantly higher scores on the COP than the children in the NP group on the total scores and on all individual items (all ps < .01) except Item 17 (overly passive; p 5 .12). These results indicate that the P group exhibited proprioceptive difficulties that were identified by the COP and that this observational tool differentiates between children with and without proprioceptive difficulties. Criterion Validity The three right columns of Table 3 present the results of the Pearson’s correlation analysis comparing individual COP items with the KIN and the SWB tests from the SIPT and the Body Awareness section items of the SPM– Home Form for the 24 children with known delays in developmental abilities. Among the COP items correlating with the SIPT subtests, only Item 9 (inefficient grading of force) correlated significantly with KIN, whereas four items in the COP (Items 4, inefficient ankle strategies; 9, inefficient grading of force; 10, decreased fluidity of movements; and 15, tendency to lean) correlated significantly with SWB. Additionally, Items 2 (joint hypermobility), 1 (decreased muscle tone), 4 (inefficient ankle strategies), and 5 (inadequate weight-bearing patterns) correlated marginally with KIN, and Item 7 (decreased feedback-related motor planning) correlated marginally with KIN and SWB. All correlations between Table 2. Body Awareness Items in the Sensory Processing Measure Home Form Item No.
The correlational analyses of the COP with these two tests thus support the use of the COP as an observational tool measuring two distinct influences of proprioceptive functions: motor performance and sensory seeking. Interrater Reliability To examine preliminary interrater reliability, four occupational therapists who had a minimum of 2 yr of experience and who had received a 15-min training on the COP rated four 20-min videotaped evaluation and regular treatment sessions of children who had been identified as having proprioceptive difficulties. We examined each item individually using the k statistic for multiple cases and raters because the responses were categorical (always, most of time, sometimes, rarely, never; Fleiss, 1971, 1981). The overall k statistic is .62, which indicates substantial agreement among the raters beyond chance. Next, to examine reliability for total scores, we converted the responses numerically before calculating the intraclass correlation coefficient (ICC).
The total score revealed an ICC of .91, indicating that variation among the four raters was minimal. In summary, occupational therapists who have at least 2 yr of clinical experience can reliably administer the COP to children referred to occupational therapy because of motor and behavioral difficulties. Exploratory Factor Analysis Table 3 displays factor loadings from the exploratory factor analysis and correlations of COP items with items from the SPM and SIPT. The negative correlations with KIN and SWB are attributable to measurement differences; higher Table 3. Factor Loadings for Exploratory Factor Analysis and Correlations With Items From the SPM and SIPT Factor COP Item EFA With Oblique Rotation F1 F2 F3 F4 KIN (SIPT) SWB (SIPT) BOD (SPM) 1. Tone and joint alignment 2. Joint hypermobility .822 .079 2.021 2.104 2.37 1. Decreased muscle tone .774 2.037 2.086 .154 2.37 3. Poor joint alignment .674 .018 .164 .093 2. Behavioral manifestations 13. Pushing 2.013 .752 .094 .125 16. Overactive 2.065 .629 .061 2.305 18. Crashing, falling, running .070 .694 .136 2.064 Item 49: .63* Item 53: .44* 14. Enjoyment when pulled .067 .671 2.126 2.038 Item 53: .44* 12. Tiptoeing 2.041 .453 2.161 .288 3. Postural motor 6. Decreased postural control 2.045 2.116 .758 .154 Item 55: .47* 15. Tendency to lean .116 .026 .696 2.078 2.46* Item 49: .47* Item 52: .48* Item 53: .41* 9. Inefficient grading of force 2.047 .349 .525 .086 2.41* 2.41* 5. Inadequate weight bearing .440 2.150 .501 .027 2.38 2.39 4. Inefficient ankle strategies .296 .052 .404 .214 2.37 2.49* 4. Motor planning 7. Decreased feedback planning .077 .089 .104 .733 2.39 2.38 8. Decreased feed-forward planning .097 .132 .159 .530 .36 17. Overly passive Not included in factor analysis 10. Decreased fluidity of movements .035 2.272 .089 .472 .51* Note. Negative correlations with KIN and SWB reflect measurement differences; higher scores on the COP and BOD correspond to more severe dysfunction, whereas higher scores on KIN and SWB correspond to lesser severity.
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