Morris Duhaime

Functional gait asymmetry in able-bodied subjects

Abstract Symmetry is assumed in unilateral gait studies or when pooling right and left limb data. The purpose of this study was to identify which muscle powers and associated mechanical energies were related to the support and propulsion functions using Principal Component Analysis (PCA). Nineteen able-bodied male subjects participated in this study. They were all right-hand and leg dominant. Simultaneous bilateral three-dimensional data were collected from an eight-camera video system and two force plates. The PCA method was used to reduce and categorize the peak muscle powers and mechanical energies calculated at the hip, knee and ankle in each plane. Students t-test for paired data was applied to determine significant differences between the identified gait parameters. The limb which had a propulsion function was characterized by a strong third hip power at push off. Most of the parameters identified by the PCA were associated with the hip, and were mainly in the sagittal plane. These parameters were concentrated during push-off. There was a secondary support function which occurred during midstance. For the limb having a supporting function, most of its activities were associated with the knee, and were spread throughout the stance phase.

Cubitus Varus Deformity Following Supracondylar Fractures of the Humerus in Children

Summary A retrospective study of 63 patients with cubitus varus deformity following supracondylar fracture of the humerus was carried out in order to identify the causes of cubitus varus, to define the best method for prevention, and to evaluate the indications for and results of treatment of the established deformity. There was no evidence of growth disturbance in any of our patients after a mean follow-up of 5 years postfracture. Cubitus varus was found to be secondary to medial tilting of the distal fragment. Failure to recognize this initial or subsequent medial tilt during early treatment of the fracture was the major factor in the development of cubitus varus deformity, thus explaining the average delay in diagnosis of 6 to 10 weeks postfracture. Since all patients regained essentially normal use of the upper extremity after the fracture, cosmesis was the primary indication for corrective surgery. Fifteen supracondylar osteotomies are reported with 33% unsatisfactory results. Prevention of this deformity by careful clinical and radiological evaluation during initial treatment of the supracondylar fracture is emphasized.

Bilateral gait patterns in subjects fitted with a total hip prosthesis.

OBJECTIVES The purpose of this report was to determine whether the muscle powers and the mechanical energies developed during the push-off period of the gait cycle of patients having a total hip prosthesis were different from able-bodied subjects as well as the effect on the nonoperated limb. DESIGN Case control study. SETTING All patients where independent and functional. PATIENTS Four patients participated in the study. The indication for surgery was degenerative arthritis of the hip. There was also an able-bodied group. INTERVENTION A Harris-Galante total hip prosthesis was used to restore hip stability and function. The patients were all operated on by the same orthopedic surgeon and had the same type of total hip replacement. MAIN OUTCOME MEASURE Gait analyses showed that not only the hips of the surgical group were affected but also the knees. RESULTS Peak power did not show any significant difference except for a decrease in the frontal plane of the operated hip power absorption. The operated hip developed 35% and 48% less energy than that of the able-bodied group in the sagittal and frontal planes, respectively. The nonoperated hip was also affected and developed 35% more energy in the sagittal plane than the operated limb but 20% less than that of the able-bodied group. There was a reduction of 47% in the energies developed in the knees of the surgical patient group. CONCLUSION These results confirmed the presence of some mechanical dysfunction in the nonoperated limb.

Simultaneous bilateral 3-D able-bodied gait

Abstract This paper reports on the muscle powers and mechanical energies developed during gait by the lower limbs over two consecutive cycles. Nineteen male able-bodied subjects participated in this study. An 8-camera video system filmed the subjects bilaterally as they walked at their natural speed over two force plates. A 3-dimensional inverse dynamic analysis was carried out to determine joint moments, powers and mechanical energy at each joint and in all planes for a total of 57 trials. The walking speed (1.30 m/s), the cadence (106.5 steps/min) and the stance phase relative duration (60.7% of the gait cycle) of the right limb were not significantly different from those of the left limb. The limb muscle peak powers were mostly different in the sagittal plane and reflected gait adjustments rather than asymmetry in gait. Generally, these differences occurred during absorption bursts. The total positive work was similar for both limbs and was associated with maintaining a similar walking speed for each limb. The right limb developed a significantly greater total negative work than the left limb. This was associated with the control of the lower limb in locomotion.

Muscle power compensatory mechanisms in below-knee amputee gait

Sadeghi H, Allard P, Duhaime M: Muscle power compensatory mechanisms in below-knee amputee gait. Am J Phys Med Rehabil 2001;80:25–32. Objective This three-dimensional and bilateral gait study on five below-knee amputees was undertaken to demonstrate the following: (1) how hip muscle powers can compensate for the lack of ankle function on the amputated side; and (2) how these compensatory mechanisms can influence muscle power activities in the sound limb. Design Gait data were assessed by an eight-camera high-speed video system synchronized to two force plates. The three-dimensional mechanical muscle powers were calculated at the joints of the lower limbs. Significant differences between each limb were determined using the Student’s t test for paired data with P < 0.05. Results In the absence of ankle plantar flexor power, hip extensors and flexors as well as hip external rotators became the major power generators, whereas hip abductors and adductors and knee extensors muscle powers became the main source of absorption. For the sound limb, increased hip extensor activity was observed, accompanied by less hip abduction-adduction activity. Conclusions Perturbations in below-knee amputee gait affected the hip muscle powers on the amputated side in all three planes, although the hip frontal plane balance was modified in the sound limb.

Classification of able-bodied gait using 3-D muscle powers

Abstract The purpose of the paper was to determine if more than one gait pattern exists in able-bodied young men, by analyzing the dissimilarities in the three-dimensional (3-D) muscle powers, developed at the joints of the right lower limb. The subjects were members of the general community and they were evaluated in an attempt to extract normative data. Nineteen young male volunteers participated in the study, all of them were able-bodied, right-sided, they did not have any orthopedic or neurological disorders which could affect their walking pattern. Multiple gait trials were used for the classification of the peak muscle powers using cluster analysis. The detailed description of the clusters was based on a multivariate general linear model. The peak values of the 3-D muscle power patterns for each of the lower extremity joints were determined by the inverse dynamic approach. Five distinct able-bodied gait patterns were identified by means of the cluster analysis classification method of 56 trials from the 19 subjects. The principal gait parameters identified in the classification process were: (a) at heel-strike, the sagittal and frontal peak hip powers, (b) at mid-stance, the sagittal and frontal knee peak powers, and (c) at push-off, all sagittal peak powers as well as the frontal hip peak powers. The variability observed in able-bodied gait may be the result of multiple normal dynamic strategies employed by the different subjects.

Natural history of scoliosis in Friedreich's ataxia.

Does scoliosis associated with Friedreichs ataxia behave like an idiopathic or a typical neuromuscular scoliosis? Should it be treated like an idiopathic or a neuromuscular curve? Since no precise information to answer these questions could be found in the orthopaedic literature, a retrospective study was undertaken of seventy-eight patients with Friedreichs ataxia who had been followed at our neuromuscular clinic. Fifty-six of these patients were found to have typical Friedreichs ataxia in accordance with the criteria of Geoffroy et al., and their cases were retained for analysis. Their mean age was twenty years (range, eight to thirty-three years). The average length of clinical follow-up was nine years and the average duration of radiographic follow-up of the scoliosis was 3.5 years. A scoliosis of more than 10 degrees was found in all patients and was associated with a hyperkyphosis in 66 per cent. Both sexes were equally affected. Fifty-seven per cent of the curves were double thoracic and lumbar; 14 per cent were thoracolumbar; 7 per cent, double thoracic and thoracolumbar; 7 per cent, thoracic; 4 per cent, lumbar; and 11 per cent, multiple small curves. Of the fifty-six patients whose cases were studied, thirty-six had been followed for at least ten years. Among these thirty-six, there were twenty whose curves were more than 60 degrees and progressed (Group I) and sixteen whose curves were 40 degrees or less and did not progress (Group II).(ABSTRACT TRUNCATED AT 250 WORDS)

Complications of limb-lengthening in children who have an underlying bone disorder

We retrospectively reviewed the results, particularly with regard to complications, of lengthening of long bones in eight children (nine limb segments) who had a limb-length discrepancy secondary to an underlying bone disorder (Group 1). The mean age of these patients was twelve years (range, six to sixteen years), the mean preoperative limb-length discrepancy was 6.0 centimeters (range, 2.7 to 8.8 centimeters), and the mean lengthening of the nine limb segments was 6.2 centimeters (range, 2.7 to 9.0 centimeters). Only two extremities were equalized. We compared the results in Group 1 with those of limb-lengthening in seven children (nine limb segments) who had a discrepancy secondary to post-traumatic growth arrest (Group 2) and seven children (seven limb segments) who had a discrepancy secondary to growth arrest following an infection in the bone (Group 3). All of the procedures were performed at our institution during the same time-period by the same surgeons. There were forty-one complications (twenty-five minor and sixteen major), with a mean of five complications per limb segment, in Group 1; twenty-six complications (twenty minor and six major), with a mean of three complications per limb segment, in Group 2; and twenty-two complications (fourteen minor and eight major), with a mean of three complications per limb segment, in Group 3. The results in Group 1 suggest that the Ilizarov technique for lengthening, although effective in restoring the length of the extremity, is associated with a higher rate of complications in patients who have a discrepancy due to an underlying bone disorder than in those who have a discrepancy due to growth arrest. Therefore, caution should be exercised before a lengthening procedure is recommended for a patient who has an underlying bone disorder.

Lower limb muscle power relationships in bilateral able-bodied gait.

Sadeghi H, Sadeghi S, Allard P, Labelle H, Duhaime M: Lower limb muscle power relationships in bilateral able-bodied gait. Am J Phys Med Rehabil 2001;80:821–830. ObjectiveThe purpose of this study was to test the hypothesis that limb propulsion is mainly associated with the interaction of a number of muscle power bursts developed throughout the stance phase and that the control actions are mainly achieved by the contralateral limb through different power-burst interactions. We also hypothesized that the power activities of the propulsion limb would be related to those of the control limb. DesignSixty gait trials of 20 subjects with dominant right hands and right legs were chosen for analysis. Each trial represents a performance of an able-bodied gait. Data were assessed using an eight-camera, high-speed, video-based system synchronized to two force plates. The muscle powers and their related mechanical energies were calculated at each joint and in each plane of the lower limbs by use of an inverse dynamic technique. The Pearson correlation method was used to determine the relationships within each limb by use of the data identified by principal component analysis, whereas a canonical correlation analysis was performed to illustrate the interaction between the limbs. ResultsGait propulsion was an activity initiated by the hip shortly after heel-strike and maintained throughout the stance phase. Control was the main task of the left limb as evidenced by the power absorption bursts at the hip and knee. The left limb power generations were generally secondary to control activities and were possibly involved in adjustments to correct the other limb’s propulsion. Interlimb interaction further emphasized the functional relationship between forward progression and control tasks developed by each limb and highlighted the importance of the frontal and transverse plane actions during gait. ConclusionThese results do not support the hypothesis that the ankle was a major contributor to forward progression.

Congenital kyphosis by segmentation defect: etiologic and pathogenic studies.

Sixteen cases of type II congenital kyphosis were reviewed. As a working hypothesis, we assumed that this pathology should have a behavior similar to scoliosis due to a segmentation defect, if a true unsegmented bar existed. The analysis of different parameters including the number of levels involved, the patients age, the degree of disc space involvement, and the site of deformity did not confirm this hypothesis. Furthermore, an experimental animal study failed to reproduce this congenital anomaly. It is our belief that kyphosis resulting from a “segmentation defect” represents a developmental defect of the perivertebral structures including the annulus fibrosus, the ring apophysis, and the anterior longitudinal ligament rather than a true intervertebral bar.