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ABSTRACT: This study aims to quantify and compare the accuracy of traditional radiostereometric analysis (RSA), fluoroscopic RSA (fRSA), and optical tracking systems. Three phantoms were constructed, each having three stainless steel spheres and three reflective markers. One phantom was mounted to the base of a precision cross-slide table, one to the base of a precision rotation table, and the third was mounted to each moveable tabletop. Two dial-gauges, rigidly mounted to the cross-slide table and rotation table, quantified translations and rotations. Two fluoroscopy units placed orthogonally tracked the steel spheres while a four-camera optical motion capture system tracked the reflective markers in three-dimensional space. RSA was performed with both digital radiography and fluoroscopy. Three axes of translation were tested: parallel to one fluoroscopy image, parallel to the other fluoroscopy image, and at approximately 45 degrees to each image. One axis of rotation was tested. Intraclass correlation coefficients indicated excellent agreement between the actual (dial-gauge) and measured translations for all modalities (ICCs>0.99) and excellent agreement between actual and measured rotations for RSA and fRSA (ICCs>0.99). Standard errors of measurement ranged from 0.032 mm and 0.121 degrees for RSA, to 0.040 mm and 0.229 degrees for fRSA, and to 0.109 mm and 0.613 degrees for optical tracking. Differences between actual and measured translations along the 45 degrees axis were significantly smaller than the two parallel axes. These findings suggest that under ideal conditions, accuracy of fRSA is comparable to traditional RSA, and superior to optical tracking. Accuracy is highest when measured at 45 degrees to the fluoroscopy units.
Journal of biomechanics 04/2009; 42(9):1350-4. · 2.66 Impact Factor
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ABSTRACT: To evaluate the effects of simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction on 1) the external knee adduction moment, 2) the external knee flexion and extension moments, and 3) the quadriceps, hamstrings, and gastrocnemius muscle activity during walking.
Twenty-one patients with varus malalignment of the lower limb, medial compartment knee osteoarthritis, and concomitant anterior cruciate ligament (ACL) deficiency were tested before and 1 yr after undergoing simultaneous medial opening wedge high tibial osteotomy (HTO) and ACL reconstruction during a single operation. Three-dimensional kinetic and kinematic data were used to calculate external coronal and sagittal moments about the knee. EMG data from the quadriceps, hamstrings, and gastrocnemius were used to determine coactivation ratio and activation patterns.
Neutral alignment and knee stability were achieved in all patients after surgery. The peak knee adduction moment decreased from 2.88 +/- 0.57 to 1.71 +/- 0.56%BW x Ht (P < 0.001). The early stance knee flexion moment decreased from 1.95 +/- 1.89 to 0.88 +/- 1.17%BW x Ht (P < 0.01). The late stance knee extension moment increased from 1.83 +/- 1.53 to 2.76 +/- 1.22%BW x Ht (P < 0.001). There were no significant differences in muscle coactivation or muscle activation patterns (P > 0.05).
Improving lower limb alignment and knee stability significantly alters the coronal and the sagittal moments about the knee during walking, without apparent changes in muscle activation patterns.
Medicine and science in sports and exercise 03/2009; 41(3):612-9. · 3.71 Impact Factor
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ABSTRACT: The purpose of this study was to describe the rate and distribution of treatment visits provided in an on-site, automotive plant, physiotherapy clinic over a 13-year period.
A retrospective cohort study was conducted using data collected at an on-site physiotherapy clinic (1990-2002, 65,977 visits; n = 2,636 workers).
The average age of workers was 43 +/- 9 years; most remained at work (85%) when treated. Disorders most commonly affected the shoulder, lumbar, and cervical regions; the median number of visits for these was 7, 6, and 5, respectively. Elbow disorders occurred commonly only for work-related complaints and required a median of eight visits. Rate of utilization was higher for women, with 47% of the plant's female workers attending physiotherapy in 1 year. Women had higher rates of cervical spine (12 vs. 22%) and wrist (5 vs. 10%) disorders. The two most common causes of injury reported by workers with an industrial injury were "frank injury arising out of normal employment" (51%) and "gradual onset/no frank injury" (37%). The diagnosis most often reported by the physiotherapist after initial assessment was "strain" which was similar for both industrial (43%) and non-industrial (49%) injuries. The six main departments in this automotive plant account for 93% of all industrial injuries reported. Final Assembly accounted for the largest number and highest rate of injury, although shift variability was noted in utilization rates (13 vs. 26%), despite the same tasks, shift schedules, and demographics. Although there was no control group, the number of visits to discharge was lower than reported in the literature for off-site physical therapy; there was a large reduction in claims (441-275) following introduction of the clinic and reduced duration/costs of lost time were identified by the employer as a rationale to continue and enhance the service over time.
On-site physiotherapy services can provide early, cost-effective management of WRMSD in the automotive sector. Service utilization reflects the influence of gender, job task, and shift-dynamics on rates and location of WRMSD.
Journal of Occupational Rehabilitation 01/2008; 17(4):610-22. · 2.80 Impact Factor
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ABSTRACT: The purpose of this study was to develop and evaluate the validity and reliability of a Pediatric Reach Test (PRT).
The Functional Reach Test was modified to incorporate side reaching in addition to forward reaching in both sitting and standing. Nineteen children developing typically (age 3.0 to 12.5 years) completed the standing section of the PRT as well as laboratory force platform tests of standing balance. On two separate occasions, two different raters evaluated 10 children with cerebral palsy (age 2.6 to 14.1 years) in both the sitting and standing sections of the PRT.
Concurrent validity was supported with the observation of moderate-to-high correlations between the standing section of the PRT and laboratory tests of limits of stability (r = 0.42 to 0.77). Construct validity was supported with the observation of high correlations between the standing section of the PRT and a laboratory test of steadiness in quiet stance (r = -0.79) and age (r = 0.83). Construct validity was also supported with a high correlation between the total PRT score and Gross Motor Function Classification System level (rs = -0.88) among the sample of children with cerebral palsy. Test-retest reliability and inter-tester reliability with children with cerebral palsy ranged from intraclass correlation coefficients of 0.54 to 0.88 and 0.50 to 0.93, respectively.
This study provides evidence that the PRT is a simple, valid, and reliable measure with potential for use with children.
Pediatric Physical Therapy 02/2003; 15(2):84-92.
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