Kinematic gait analysis in dogs with hip dysplasia

OBJECTIVE: To define alterations of movement in dogs with hip dysplasia by use of noninvasive, 3-dimensional, computer-assisted kinematic gait analysis. DESIGN: Kinematic and force plate data were collected at the trot from clinically normal dogs and from dogs with hip dysplasia. ANIMALS: 12 large adult dogs of various breeds with clinical and radiographic evidence of hip dysplasia, and 12 clinically normal adult large dogs of various breeds with body weight similar to that of the dogs with hip dysplasia. PROCEDURE: Dynamic flexion and extension angles and angular velocities were calculated for the coxofemoral, femorotibial, and tarsal joints. Temporal and distance variables were also computed. Essential Fourier coefficients were determined and used to reconstruct mean dynamic flexion and extension curves for all joints, and to compare differences in movement between dogs with hip dysplasia and clinically normal dogs. RESULTS: Dogs with hip dysplasia had subtle characteristic changes in dynamic flexion and extension angles and angular velocities of each joint, verified by significant differences in essential Fourier coefficients between the 2 study groups. Stride length was increased and peak vertical force was decreased in dogs with hip dysplasia. Subject velocity, maximal foot velocity, stance duration, stride frequency, and impulse area did not differ between the 2 groups. CONCLUSIONS: Kinematic gait analysis indicated that hip dysplasia is associated with alterations in movement of the coxofemoral, femorotibial, and tarsal joints. Computer-assisted kinematic gait analysis provided a noninvasive, objective tool with which to evaluate these complex motion alterations. CLINICAL RELEVANCE: The information obtained may be useful in future evaluations of various modes of treatment for hip dysplasia.     

Rehabilitation of dogs with surgically treated cranial cruciate ligament-deficient stifles by use of electrical stimulation of muscles

OBJECTIVE: To determine effect of electrical muscle stimulation (EMS) on rate and degree of return to function of the limb and development of degenerative joint disease (DJD) after surgical creation and subsequent stabilization of the cranial cruciate ligament (CrCL)-deficient stifle. ANIMALS: 12 clinically normal adult large (19.5 to 31.5 kg) dogs. PROCEDURE: Dogs were anesthetized, and the right CrCL was severed via arthrotomy, destabilizing the stifle. After 3 weeks, the stifle was surgically stabilized. Three weeks later, 6 dogs were subjected to an EMS treatment protocol for the thigh muscles. At 5, 9, 13, and 19 weeks after stifle destabilization, treated (n = 6) and control (n = 6) dogs were evaluated for return of stifle function. Gross and histologic evaluations of the stifles were performed at 19 weeks after stifle destabilization. RESULTS: Treated dogs had significantly (P = 0.001) better lameness score than did control dogs. There was less palpable crepitation of the stifle in treated dogs (P = 0.06); treated dogs also had significantly (P = 0.01) fewer radiographic signs of bone changes. Thigh circumference was significantly (P = 0.02) larger in treated dogs. There was less gross cartilage damage (P = 0.07) in the EMS-treated dogs, but more medial meniscal damage (P = 0.058, cranial pole; P = 0.051, caudal pole). CONCLUSIONS: Improved lameness scores, larger thigh circumference, and decreased radiographically apparent bony changes observed for the treated group of dogs support the hypothesis that dogs treated by EMS after surgical stabilization of the CrCL-deficient stifle had improved limb function, with less DJD, than did dogs treated with the currently accepted clinical protocol of cage rest and slow return to normal activity. However, results of force plate evaluation did not support the hypothesis. Increased meniscal damage in dogs treated by EMS may be cause for concern.     

Reliability of the hip distraction index in two-month-old German shepherd dogs

OBJECTIVE: To determine whether distraction index (DI), a measure of passive hip joint laxity, at 2 months of age was predictive of DI at 4 or 12 months of age in German Shepherd Dogs. DESIGN: Prospective cohort study. ANIMALS: 45 German Shepherd Dogs. PROCEDURE: DI was measured at 2, 4, and 12 months of age. At the same times, a standard ventrodorsal radiographic projection of the pelvis with the hip joints extended was obtained and examined for evidence of degenerative joint disease (DJD). To facilitate radiographic positioning, dogs were sedated or anesthetized. RESULTS: DI at 2 months of age was not significantly correlated with DI at 4 or 12 months of age. However, DI at 4 months of age was correlated with DI at 12 months of age. The proportion of dogs with DI > or = 0.3 at 12 months of age that had radiographic evidence of DJD by 12 months of age (13/22; 59%) was significantly greater than the proportion of dogs with DI < 0.3 at 12 months of age that had radiographic evidence of DJD by 12 months of age (1/9; 11%). CLINICAL IMPLICATIONS: For German Shepherd Dogs, DI at 2 months of age was not sufficiently reliable to predict DI at 4 and 12 months of age; however, DI at 4 and 12 months of age were comparable. We recommend that, for German Shepherd Dogs, DI not be measured before 4 months of age and that particularly for breeding dogs, DI be remeasured after maturity to confirm DI obtained at earlier ages. Studies including other breeds of dogs should be done to determine the youngest reliable age to initiate hip joint screening.     

Epidemiologic and genetic studies of canine hip dysplasia in a population of Labrador retrievers: a study over 25 years

The occurrence of canine hip dysplasia (CHD) was analyzed in a colony of 738 Labrador Retrievers between 1972 and 1996. Of these dogs, 86.3% were radiographically examined for hip dysplasia. The overall prevalence of CHD was 31.3% during the study period of 25 years. Between 1972 and 1980, the prevalence of CHD was 57.9%. It decreased to 14.9% between 1991 and 1996. Univariate and multivariate logistic regression models were developed to identify the influence of potential risk factors for CHD such as age at examination, gender, color, year and season of birth, litter size, order of birth, birth weight, body weight and daily weight gain. Birth year and age at examination proved to be significant risk factors. No significant association was found between CHD and elbow dysplasia. Of the dogs diagnosed with CHD, 18% showed dysplastic changes only, without radiographic signs of secondary osteoarthritis (OA). The Norberg angle (NA) proved to be a significant risk factor for coxofemoral osteoarthritis with a moderate negative correlation between OA and NA. Finally, genetic effects were calculated in a mixed model. Heritability (h2) of CHD was estimated at 0.53 (SE = 0.17) for paternal half siblings. The proportion of the common environment of a litter to the total variance was estimated at C2 = 0.03.     

Hip motion and moments during gait relate directly to proximal femoral bone mineral density in patients with hip osteoarthritis

The present study examined the loads at the hip joint during gait and the bone mineral density of the proximal femur in 25 patients with end-stage hip osteoarthritis. Dual energy X-ray absorptiometry was used to determine the bone mineral density of the greater trochanter, femoral neck and Ward's triangle of the osteoarthritic group. The bone mineral density was normalized for the patient's age, gender, weight and ethnic origin (Z score). Gait analysis was used to determine the external hip joint moments and motion during walking for the osteoarthritic group and a control group of 21 normal subjects. The gait parameters of the osteoarthritic group which were significantly diminished compared to the normal group (p < 0.001) accounted for as much as 42% (p < 0.001) of the variation in the normalized bone mineral density. Specifically, the dynamic sagittal plane hip motion during gait (maximum flexion minus maximum extension) and peak external rotation and adduction moments were significantly correlated with greater trochanter (R = 0.429-0.648, p = 0.032-0.0001) and Ward's triangle (R = 0.418-0.532, p = 0.038-0.006) normalized bone mineral density while the adduction moment was also significantly correlated with the femoral neck normalized bone mineral density (R = 0.5394, p = 0.005). The normalized bone mineral density of the femoral neck and Ward's triangle was elevated while that of the greater trochanter was decreased as compared to normal reference values. The significant correlation between the hip joint moments during gait and femoral bone mineral density indicate that hip joint loads need to be included when explaining local variation in bone mineral density in hip osteoarthritis.     

The intertrochanteric osteotomy in the treatment of congenital dysplasia of the hip

The dysplastic acetabulum develops to normal shape only if the head of the femur is in central position in the articualr cavity correct according to biomechanics of the hip joint. Anterior rotation of the neck of the femur should be reduced operatively to neutral position as soon as possible if joint congruity cannot be achieved by conservative treatment. The indication for an intertrochanteric derotation osteotomy is made in cases demonstrating a roof inclination less than 30 degrees in children age 1 1/2 to three. After the third year of age, the mutual growth-stimulating effect of the articular bodies is not important enough to be useful in treatment of dysplasia. The femoral osteotomy has to be performed intertrochanterically. If articular congruity cannot be achieved by intertrochanteric osteotomy only, an additional innominate osteotomy of the pelvis is indicated at the same stage. The results of 435 cases demonstrated a good development of the acetabular roof if the intervention was performed early, according to correctly specified indications. In cases with insufficient growth potential of the acetabular roof, resulting in an increased inclination, an additional reconstruction of the acetabular cavity is required.     

Association between pelvic muscle mass and canine hip dysplasia

OBJECTIVE: To investigate the relationship between pelvic muscle mass and development and expression of canine hip dysplasia (CHD). DESIGN: Prospective study. ANIMALS: 5 Greyhounds with anatomically normal hip joints, 59 German Shepherd Dogs (23 with CHD, 24 with near-normal hip joints, and 12 with normal hip joints), and 18 German Shepherd Dog-Greyhound crossbreeds (7 with CHD, 6 with near-normal hip joints, and 5 with normal hip joints) between 12 and 47 months old in which pelvic muscle mass was evaluated. Pectineal muscle and hip joint development were evaluated in 25 German Shepherd Dogs at 8 and 16 or 24 weeks of age. PROCEDURES: For evaluation of pelvic muscle mass, individual pelvic muscles were weighed and hip joints were assigned a score on the basis of severity of degenerative changes. For evaluation of pectineal muscle development, muscle sections were stained and examined. RESULTS: Pelvic muscle mass was greatest in Greyhounds, intermediate in crossbred dogs, and smallest in German Shepherd Dogs. Differences in pelvic muscle mass among breeds were attributable to differences in weights of individual muscles. Hip score was negatively correlated with pelvic muscle mass and weights of selected pelvic muscles. Dogs with pectineal hypotrophy at 8 weeks of age had type-2 muscle fiber paucity or muscle fiber-type grouping at 16 or 24 weeks of age. At 8 weeks of age, hip joints were composed of multiple centers of ossification, and the acetabulum was largely cartilaginous. By 24 weeks of age, the pelvic bones were largely, although incompletely, fused. CLINICAL IMPLICATIONS: Diminished pelvic muscle mass in dogs with CHD and altered muscle fiber size and composition in 8-week-old dogs that subsequently develop CHD strongly suggest that abnormalities of pelvic musculature are associated with development of CHD. The complex development of the hip joint from multiple centers of ossification may make the joint susceptible to abnormal modeling forces that would result from abnormalities in pelvic muscle mass.     

Comparison of the combined cortical thickness of the second metacarpal with Sharp's method for scoring hand microradiographs in rheumatoid arthritis

OBJECTIVE: To compare the correlation and specificity of the combined cortical thickness of the second metacarpal (CCT-MC) with Sharp's method (SM) for scoring joint erosions and joint space narrowing in rheumatoid arthritis (RA) and to compare the degree of interobserver agreement between the 2 methods. METHODS: Hand microradiographs of 22 women with RA, functional classes III and IV, were scored independently by 3 rheumatologists using the CCT-MC and the CCT of the middle phalanx and SM. RESULTS: (1) There was a highly significant correlation between the total SM score and the CCT-MC for the 3 observers (r = 0.61, p = 0.0026), but not between the CCT of the middle phalanx and SM (r = 0.15, p = 0.53). There was a lower degree of agreement between the observers for SM erosion scores compared to the CCT-MC (intraclass correlation 0.88 for the CCT-MC and 0.63 for the SM); (2) Both joint space narrowing and erosion scores correlated highly with the CCT-MC (r = -0.60, p = 0.004; and r = -0.51, p = 0.014, respectively); (3) CCT-MC measurements are more closely related to the inner (d) as opposed to the outer (D) diameter of the 2nd metacarpal; (4) The mean time to obtain the CCT-MC score was 3.43 min (SD = 1.38) versus 9.83 min (SD = 3.20) for SM (p = 0.0001); (5) the derivative, (D2-d2)/D2, was significantly correlated with SM (r = -0.72, p = 0.0002) and its erosion and joint space narrowing components (r = -0.63, p = 0.0019; and r = -0.71, p = 0.0002, respectively). CONCLUSION: The CCT-MC is a rapid, practical method with higher agreement among observers compared to SM and correlates highly with SM scores for joint damage in RA. CCT-MC appears to have a higher degree of specificity than other sites for CCT measurement. The CCT-MC is more closely related to the inner diameter than the outer diameter, which supports the notion that the principal site of accelerated bone loss due to RA in the hand occurs at the endosteal surface. The CCT-MC should be further assessed with respect to monitoring radiological progression in RA.     

Retrospective cohort study of changes in hip joint phenotype of dogs in the United States

OBJECTIVE: To determine whether there had been a significant improvement in hip joint phenotype of dogs in the United States by comparing results of evaluations done by the Orthopedic Foundation for Animals of dogs born between 1972 and 1980 with those of dogs born between 1989 and 1992 and determining whether there had been an increase in the percentage of dogs classified as having excellent hip joint phenotype. DESIGN: Retrospective cohort study. SAMPLE POPULATION: 270,978 evaluations. PROCEDURE: Numbers and percentages of dogs classified as having excellent hip joint phenotype during each period and change between periods in percentages of dogs classified as having excellent hip joint phenotype were calculated. RESULTS: Percentage of dogs born between 1989 and 1992 that were classified as having excellent hip joint phenotype (15,289/143,668; 10.64%) was significantly higher than percentage of dogs born between 1972 and 1980 that were classified as having excellent hip joint phenotype (9,960/127,310; 7.82%). The increase in percentage of dogs classified as having excellent hip joint phenotype was significantly higher for male (51%) than for female (27%) dogs. CLINICAL IMPLICATIONS: Results suggest that there has been an improvement in the hip joint phenotype of dogs in the United States between the 1970s and early 1990s and that the improvement has been greater among male than among female dogs.     

Serum concentrations of cartilage oligomeric matrix protein and bone sialoprotein in hip osteoarthritis: a one year prospective study

OBJECTIVE: To evaluate serum concentrations of cartilage oligomeic matrix protein (COMP) and bone sialoprotein (BSP) as predictors of disease progression in hip osteoarthrtitis (OA). METHODS: Forty eight consecutive patients, referred to hospital for symptomatic hip OA, (ACR criteria) were monitored in a one year prospective trial with radiographs and serum samples. The radiographs were graded for joint space narrowing, osteophytes, and sclerosis and the joint space width was measured by a digitised image analyser. Serum COMP and BSP were quantified by immunoassays. RESULTS: The COMP concentrations at baseline correlated with the joint space width at entry and with its yearly mean narrowing (r = 0.38, p = 0.002) but not with joint space narrowing grade progression. The concentrations were higher in patients with bilateral hip OA (p = 0.03). The serum BSP concentrations at baseline were unrelated to OA progression but correlated inversely to the osteophyte grade (r = -0.36, p = 0.004) and sclerosis grade (r = -0.42, p = 0.0004). CONCLUSION: Serum COMP seems to be a surrogate marker of OA and may be of interest for the detection of patients at risk of rapidly progressing disease in hip OA. Serum BSP changes seem to reflect alterations in the subchondral bone turnover in hip OA. Measurement of joint space width using a digitised image analyser is a sensitive way of assessing OA progression that facilitates evaluation of tissue markers in relation to anatomical changes in the joint.     

Progressive diaphyseal dysplasia: a three-generation family with markedly variable expressivity

The purpose of this study was to examine the intrasubject reproducibility of the kinematic and kinetic measures of the lower extremity during normal stair-climbing. Three-dimensional video and force-plate data were collected for three trials per subject during each of three conditions: ascending, descending, and level walking. Three-dimensional angles and moments of the ankle, knee, and hip joints were calculated. The coefficient of multiple correlation was used to determine the intrasubject reproducibility of joint angles and resultant moments. Analysis of variance with repeated measures was conducted to compare the magnitudes of the coefficients between different steps, different joints, and different joint functions. The results showed that (a) generally, the kinematic and kinetic measures of normal subjects climbing stairs were reproducible; (b) the kinetic measures during the transition steps from level walking to ascending and from descending to level walking were significantly less reproducible than those during the other steps; (c) the data from the sagittal plane were more reproducible than those from the other two planes; and (d) the kinetic measures were more reproducible than the kinematic measures, especially for abduction-adduction and internal-external rotation.     

Bulk effect of rotator cuff on inferior glenohumeral stability as function of scapular inclination angle: a cadaver study

Eleven fresh cadaver shoulders were studied to determine the static contribution (bulk effect) of the rotator cuff on inferior glenohumeral stability provided by scapular inclination. All musculature, including the rotator cuff, was removed. The position of the humerus relative to the scapula was recorded using an electromagnetic tracking device under conditions of no force and 1.5 kg of inferior translation force applied to the humerus, with the arm in the hanging position (sulcus test) and then in 90 degrees abduction (Abduction-Inferior Stability test = ABIS test), with the scapula inclined referable to the vertical line at -15 degrees, 0 degrees, 15 degrees and 30 degrees in the sulcus test and at 15 degrees, 30 degrees, 45 degrees and 60 degrees in the ABIS test. In the sulcus test without load, all shoulders dislocated at scapular inclination angles of -15 degrees and 0 degrees, whereas no shoulders dislocated at 30 degrees. The angle of scapular inclination had a significant effect on humeral head positions (p < 0.0001), with the head position at -15 degrees and 0 degree being lower than at 15 degrees, which was lower than at 30 degrees. In the ABIS test, none of the shoulders dislocated, although the effect of the angle of scapular inclination was significant (p < 0.0001), with the position of the humeral head being higher at 15 degrees than at other angles of inclination. Comparison of these data and previously reported data with the cuff intact showed no significant effect of rotator cuff removal on humeral head position and displacement in both tests. Therefore, we conclude that the static condition of the rotator cuff has no significant effect on the stabilizing function of scapular inclination. The stabilizing mechanism of scapular inclination seems to be associated with the bony configuration and/or anatomy and biomechanical properties of the superior capsuloligamentous structures.     

L-arginine decreases alveolar macrophage proinflammatory monokine production during acute lung injury by a nitric oxide synthase-dependent mechanism

The hip abductor muscles are considered important for gait and biomechanics of the hip joint; however, their specific function has not been defined precisely. The intensity of magnetic resonance imaging signals in skeletal muscle has been reported to increase immediately after exercise. Making use of this phenomenon, we evaluated the hip abductor muscles. Magnetic resonance imaging was performed after isometric exercise of the hip abductor in three positions (20 degrees of abduction, neutral, and 20 degrees of adduction). The abduction force of the hip was measured with a dynamometer, and electromyographic measurements were made simultaneously for the same hip positions. Additionally, magnetic resonance imaging was performed after one-legged stance. As the hip was more adducted, the signal intensity increased on the scans. The values for muscle force, as evaluated with the dynamometer and integrated electromyography, also supported the results. The increase in signal intensity of the gluteus minimus at 20 degrees of abduction and after one-legged stance was significantly greater than that of the gluteus medius (p < 0.0001 and p < 0.0001, respectively). The results of this study indicate that the gluteus minimus muscle, along with the gluteus medius, plays an important role in hip abduction, gait, and stabilization of the pelvis.     

Cardiovascular stabilization after hemorrhage depends upon restitution of blood volume

The role of late restitution of blood volume after hemorrhage in cardiovascular stabilization was examined in awake, splenectomized dogs. Cardiovascular variables were measured: at 2 hours after hemorrhage, changes were noted in cardiac output, mean arterial pressure, heart rate, stroke volume, arterial pressure, and CVP in three hemorrhage groups (p less than 0.05), and in total peripheral resistance for 15 ml/kg and 22.5 ml/kg hemorrhage groups (p less than 0.05). At 24 hours after hemorrhage, the degree of restitution of blood volume was correlated with cardiac output (p less than 0.01), stroke volume (p less than 0.02), and total peripheral resistance (p less than 0.01). No correlation was noted with heart rate, CVP, or mean arterial pressure. Blood volume restitution was correlated with degree of hemorrhage throughout the 24-hour period of investigation. Plasma protein content restitution and blood volume restitution were correlated with changes in osmolality. The results suggest thatcardiovascular stabilization after hemorrhage is a function of the degree of restitution of blood volume mediated through a shift of fluids to the interstitutium, mediated in turn by extracellular hyperosmolality.     

Biodistribution and pharmacokinetics of 131I-labeled LEX 032, a recombinant hybrid of antichymotrypsin

Computed tomographic (CT) scans were performed after closed reduction of 68 dislocated hips in 53 infants in spica casts with developmental hip dislocation (DDH). Ten measurements were made on the CT scans including acetabular indices and anteversion, hip-abduction angle, lateral and posterior displacement of the femur from the acetabulum, and femoral displacement from a modified Shenton's line drawn from the pubic rami. By using analysis of variance, the correlation of each variable with outcome after reduction was determined, including the development of avascular necrosis or the need for further surgery because of residual dysplasia. None of the variables was predictive of the outcome of persistent hip dysplasia. The subsequent development of avascular necrosis was statistically associated with hip-abduction angles >55 degrees as measured on postreduction CT scans, with 20% of the involved hips developing avascular necrosis on subsequent follow-up.     

Energetics of vinca alkaloid interactions with tubulin isotypes: implications for drug efficacy and toxicity

Capture ELISAs, for canine IgG, IgM, IgA and albumin, were developed and used to analyse immunoglobulin (Ig) concentrations in both serum and secretions. Matched samples of serum, saliva and tears were taken from 31 dogs, assigned to two groups based on age, whilst bile samples were obtained from nine adult dogs at post-mortem. Serum and tear IgA concentrations were significantly lower in dogs < or = 12 months of age compared with dogs > 12 months of age (p = 0.006 and 0.045, respectively). There was no significant correlation between serum and secretory Ig levels, with the single exception of serum and tear IgM concentrations (rp = 0.553, p = 0.004). IgG and IgM concentrations were significantly correlated in matched tear and saliva samples (IgG: rp = 0.470, p = 0.023; IgM: rp = 0.651, p < 0.0001). Albumin concentrations were significantly correlated with IgG, but not IgM or IgA, in both saliva and tears (saliva, rp = 0.581, p = 0.004; tears, rp = 0.843, p < 0.0001) whilst IgA and IgM concentrations were significantly correlated with each other in both secretions (saliva, rp = 0.644, p = 0.001; tears, rp = 0.555, p = 0.009). Significantly, more Ig of all classes was secreted into saliva than tears as calculated by a secretory index. A large diurnal and day-to-day variation was observed in Ig concentrations in serial saliva and tear samples taken from a further four dogs. Serum Ig concentrations are therefore, poor indicators of mucosal secretion in this species and significant intra-individual variation exists in secretory Ig levels. Both findings should be taken into account in future studies of canine mucosal immunoglobulins.     

Effect of inpatient rehabilitation measures on patients with total hip endoprostheses--evaluation 15 months after operation

159 patients were examined approximately 15 months after hip arthroplasty. 116 of these patients have had at that time point a postoperative 4 week hospital stay for rehabilitation. A score that considered pain at motion and at rest, maximal walking capacity and activity of daily living was used for evaluation. The preoperative conditions did not differ between patients that had their postoperative hospital stay for rehabilitation (n = 116) and those that did not (n = 43). The results at the time of examination were regarded as excellent (group 1; score 3) in 64 (40.3%) patients, as good (group 2; score 4) in 56 (35.2%) patients and as poor (group 3; score > or = 5) in 39 (24.5%) patients. The amount of patients with a hospital stay for rehabilitation was significantly (p = 0.025) higher in the patient groups with excellent or good results in comparison with the patients with poor postoperative outcome. The most excellent results were obtained in patients who had their rehabilitation within the first two months after surgery (p = 0.008). Apart from the above mentioned score the following-additionally assessed-parameters differed significantly between the 3 groups: hip mobility; pain elicited by pressure on the operated joint; pain in the contralateral hip or knee joints; consumption of analgetics; walking time for 15 meters; degree of handicap as assessed by the patient or the occupational therapist or the physician; coping with household activities (for females only). We conclude that a poor result of hip arthroplasty may be due not only to degenerative joint disease of the lower limbs but also (or in combination) to the lack of a postoperative hospital stay for rehabilitation.     

Criteria for a mediator or effector of myocardial preconditioning: do KATP channels meet the requirements?

We studied four indirect radiological measures of shoulder balance, their correlation with true shoulder balance, and measurement error of each method. Thirty-three consecutive patients with idiopathic scoliosis requiring surgical treatment were selected. Actual shoulder level was determined from a line in the top margin of the acromion clearly visualized in the wide chart. Indirect references used to assess shoulder balance were tilting of cephalic end-plate of T1, inclination of a line through superior border of both first ribs, the level of top margin of coracoid processes, and the level of two specific points where the clavicle intersects the rib cage. All radiographs were assessed by three independent observers. Correlation coefficients between each measurement and true shoulder level were 0.54 for T1 tilting (p = 0.001), 0.63 for first rib inclination (p < 0.001), 0.96 for coracoid process (p = 0.0001), and 0.93 for clavicle-rib cage intersection (p = 0.0001).     

Ankle, knee, and hip moments during standing with and without joint contractures: simulation study for functional electrical stimulation

Joint contractures have been one of the contraindications for use of functional electrical stimulation for standing in paraplegic patients. A simulation study using a three-segment link mechanical model of the human body was performed to calculate the muscle moments at the ankles, knees, and hips during standing with and without having joint contractures. The knee and hip angles were varied in 5 degrees increments, whereas the ankle angles were varied in 1 degree increments. It was assumed that energy efficient posture was obtained with the least sum of the squared moments of the ankles, knees, and hips joints by the muscles. Ankles at 5 degrees of dorsiflexion, knees at 0 degrees, and hips at 15 degrees of extension resulted in the most energy efficient posture without joint contractures. The muscle moments increased with the increase in angle of contractures. The joint contractures at ankle angles > or = 6 degrees of plantar flexion, knee angles > or = 20 degrees of flexion, and/or hip angles > or = 20 degrees of flexion produce a potentially unstable posture. These findings suggest that some degree of joint contractures can be tolerated in paraplegic patients using functional electrical stimulation for standing.