Roy B. Davis

Three-dimensional lower extremity joint kinetics in normal pediatric gait

Gait analysis is becoming a more integral part of the decision-making process in treatment of children with neuromuscular problems. A normal reference, however, must be available for comparison when one makes decisions. We wished to develop a normal pediatric database for joint kinematics and kinetics which could then be used as a reference for clinical gait analysis. Thirty-one normal children underwent a complete gait analysis including calculations of three-dimensional joint kinematics and kinetics. The pediatric data were similar to that of normal adults.

Alterations in surgical decision making in patients with cerebral palsy based on three-dimensional gait analysis.

The purpose of this study was to compare surgical recommendations made by clinicians experienced in gait analysis when using information provided from the clinical examination and videotape, with recommendations made after the addition of kinematic, kinetic, and electromyographic (EMG) data. Ninety-one patients with a diagnosis of cerebral palsy were seen in the gait laboratory as part of the surgical decision-making process. Experienced clinicians reviewed video and clinical examination data for each patient and made surgical recommendations. Joint kinematics and kinetics and EMG data were then reviewed, and a second set of surgical recommendations was made. Comparisons between these recommendations showed that the addition of gait-analysis data resulted in changes in surgical recommendations in 52% of the patients, with an associated reduction in cost of surgery, not to mention the human impact of an inappropriate surgical decision, which is more likely without gait analysis. When changes in recommendations were made, an increase in surgical recommendations was observed for the gastrocnemius (59%) and rectus femoris (65%), whereas decreases were observed for the hamstrings (61%), psoas (78%), hip adductors (83%), femur (86%), and tibia (64%).

Kinematic and kinetic evaluation of the ankle after lengthening of the gastrocnemius fascia in children with cerebral palsy.

Summary: The effect of surgical lengthening of the gastrocnemius fascia on ankle joint kinematics and kinetics during gait in patients with cerebral palsy (CP) was evaluated. Twenty independent ambulators (24 sides) were included in this retrospective study. The evaluation included clinical examination, calculation of joint kinematics and kinetics, and collection of surface electromyography (EMG) during gait. Postoperative improvements were noted in static heelcord range of motion (ROM), with an associated increase in dorsiflexion in stance and swing. Kinetic analysis showed a decrease in the abnormal energy generated around the ankle in midstance and a statistically significant increase in the energy generated in late stance for push-off.

Rectus femoris surgery in children with cerebral palsy. Part I: The effect of rectus femoris transfer location on knee motion.

Summary Rectus femoris transfer was performed in 78 children (105 sides) with cerebral palsy (CP) at the same time as other surgical procedures as appropriate. The transfer was either medial to the sartorius (62 sides), semitendinosus (19 sides), or the gracilis (14 sides) muscles, or laterally to the iliotibial band (10 sides). Gait analysis performed before and 1 year after operation demonstrated increased knee range of motion (ROM) with increased extension at initial contact and in midstance and maintained knee flexion in swing. There were no statistically significant differences between the four transfer sites in the effect on those variables. Therefore, the choice of rectus femoris transfer site can be dictated by surgical preference or by the nature of other simultaneous procedures. There was no consistent change in transverse plane motion of the hip or foot progression angles between the two gait analyses, suggesting that rectus femoris transfer does not affect gait abnormalities observed in the transverse plane.

Long-term effects of femoral derotation osteotomies: an evaluation using three-dimensional gait analysis.

The purpose of this study was to evaluate the long-term effects of the femoral derotation osteotomy (FDO) in the ambulatory patient with cerebral palsy (CP). The effectiveness of the FDOs were evaluated using three-dimensional gait analysis just before surgery (P0), 1 year after surgery (P1), and 5 years after surgery (P2). A total of 20 patients (27 sides) with CP were evaluated. Related physical examination and motion measures showed significant improvements at P1 that were maintained at P2. Mean maximum internal hip rotation at P0 of 77° ± 9° decreased to 53° ± 8° at P1 and was maintained at 58° ± 11° at P2. Mean maximum external hip rotation at P0 of 21° ± 11° increased to 35° ± 15° at P1 and was maintained at 32° ± 13° at P2. Mean femoral anteversion at P0 of 63° ± 9° was reduced to 26° ± 15° and was maintained at 31° ± 13° at P2. During gait, mean hip rotation in stance at P0 of 20° ± 8° was decreased to 2° ± 10° at P1 and was maintained at 4° ± 5° at P2. There were associated significant foot progression changes from an internal progression mean of 5° ± 17° at P0 to −11° ± 17° at P1 that were maintained at −12° ± 5° at P2. The findings suggest that the FDO is a viable and lasting treatment option for the correction of anteversion and associated internal hip rotation during gait in children with CP.

Effect of hamstring and psoas lengthening on pelvic tilt in patients with spastic diplegic cerebral palsy.

The purpose of this study was to evaluate the effects of hamstring lengthenings and psoas recessions over the brim of the pelvis (OTB) on pelvic function in the gait of patients with spastic cerebral palsy. Seventy-three patients were divided into four groups based on surgical intervention: medial hamstrings (n = 37), medial and lateral hamstrings (n = 12), medial hamstrings with psoas OTB (n = 9), and medial and lateral hamstrings with psoas OTB (n = 15). Three-dimensional gait analysis was completed both before and approximately 1 year after surgery. When pelvic position in gait was normal or posterior of normal preoperatively, there was a significant increase in pelvic tilt (p < 0.05) when medial and lateral hamstrings were lengthened, irrespective of simultaneous psoas OTB surgery. Medial hamstrings alone, with or without simultaneous psoas OTB, did not result in a significant change in pelvic position, irrespective of preoperative pelvic position. The only surgical combination that caused a reduction in excessive preoperative anterior pelvic tilt was medial and lateral hamstrings with psoas OTB, a 4 degrees change of limited clinical significance. In general, psoas and medial hamstring surgery have minimal effect on the pelvic position during gait. Medial and lateral hamstring lengthening will increase pelvic tilt if preoperative pelvic position is normal or slightly posteriorly tilted. The results of this study suggest that the fundamental determinants of pelvic position during gait postoperatively are the extent of hamstring surgery (medial only vs. both medial and lateral hamstring lengthening) and the preoperative position of the pelvis.

Rectus femoris surgery in children with cerebral palsy. Part II: A comparison between the effect of transfer and release of the distal rectus femoris on knee motion.

Summary Rectus femoris muscle (RF) surgery was performed in 98 children (136 sides) with cerebral palsy (CP). RF transfer was performed in 105 lower limbs, and distal RF release was performed in 31. Eleven (20 sides) similarly affected children had no RF procedure and are included for comparison. Gait analysis was performed just before and ∼1 year after surgery. All children underwent other orthopaedic surgery at the time of the RF procedure. When preoperative knee range of motion (ROM) was >80% of normal, there were no significant changes in knee motion in either the RF transfer or distal release groups. In patients with <80% of normal knee ROM preoperatively, RF transfer was followed by maintained knee flexion in swing; patients who underwent distal RF release or no RF procedure showed a decrease (10° and 6°, respectively) in knee flexion postoperatively. These results suggest that the RF should be transferred and not released when knee ROM is <80%.

Joint kinetics: methods, interpretation and treatment decision-making in children with cerebral palsy and myelomeningocele

Abstract Computerized gait analysis has become an integral part of the treatment decision-making process in many clinical settings. The integration of kinetic data, more specifically joint moments and powers, is a relatively new addition to other types of data including joint kinematics, temporal and stride parameters and electromyography. Joint kinetic data is an important contribution to the understanding of the cause of certain gait abnormalities which are not provided by the other measures. Its utility is not only limited to the surgical decision-making process in persons with cerebral palsy and myelomeningocele but also in the orthosis decision-making process. At the time of this writing, its use as a surgical decision-making tool is limited to a few types of treatment. However, systematic study of the effects of treatment on the joint kinetics and the relationship of deviations at one joint with adjacent joints will improve our understanding of these data and how they can become an integral part of the treatment decision-making process. A review of the methods, pointers on interpretation and specific data examples will provide the reader with a detailed introduction to joint kinetics.

Optimization of walking ability of children with cerebral palsy.

A new paradigm based on an appreciation of the biomechanics of normal and pathologic gait and a better understanding of muscle-tendon unit anatomy and physiology has emerged for orthopaedic clinical decision making to optimize the ambulatory abilities of children with cerebral palsy. This quantitative, biomechanically based approach has been accepted as a research and teaching tool and as an instrument of outcome assessment; however, controversy remains concerning the expense of using this approach and about its accuracy and repeatability. This paradigm is used within a diagnostic matrix consisting of five data sources. Members of the clinical and technical teams from the motion analysis laboratory interpret data from the clinical history, physical examination, diagnostic imaging, quantitative gait analysis, and examination under anesthesia. The certainty of intervention selection is proportional to the consistency of the data within the diagnostic matrix. When inconsistencies in the data exist, input from both the clinical and technical teams is needed to resolve discrepancies. Working within the framework of the diagnostic matrix, it is possible to identify the indications used in the selection and recommendation of musculoskeletal surgical interventions to optimize gait in children with cerebral palsy. It is important to examine indications and controversies for surgical intervention related to iliopsoas recession, femoral rotational osteotomy, medial hamstring lengthening, rectus femoris transfer, and gastrocnemius recession.

Prevalence of obesity in ambulatory children with cerebral palsy.

BACKGROUND According to the most recent data, an estimated 17.1% of children in the United States are obese. We found no published studies documenting the prevalence of obesity in ambulatory children with cerebral palsy. The purpose of this study was to document the prevalence of obesity in ambulatory children with cerebral palsy and examine the trend in this measure over the last decade. METHODS A retrospective review was performed to analyze the age, gender, height, weight, physical classification of the cerebral palsy, and functional level as determined with the Gross Motor Function Classification System (GMFCS) of all children with cerebral palsy who had a gait analysis performed in the Motion Analysis Laboratory of our institution between January 1994 and December 2004. This information was used to determine the prevalence of obesity (a body mass index in or above the 95th percentile of the sex-specific body mass index-for-age growth chart) in this population and its relationship to age, gender, the physical classification of the cerebral palsy, and the GMFCS level. RESULTS When the data were grouped into three time periods (1994 to 1997, 1998 to 2002, and 2003 to 2004), a significant increase in obesity over time was noted (p = 0.017). The prevalences increased from 7.7% to 14% to 16.5% in the respective time periods. The prevalence increased over time in both males and females, those with hemiplegia and those with diplegia, and those with level-I function and those with level-II function according to the GMFCS. The association between obesity and time was significant in the female (p = 0.015), hemiplegic (p = 0.049), less than eight-year-old (p = 0.020), and GMFCS level-II (p = 0.003) groups. We found that the time period was independently associated with obesity when we controlled for age, type of cerebral palsy, and GMFCS level (p = 0.014). Children with a lesser degree of involvement (GMFCS level II) had twice the odds of becoming obese than did children with greater involvement (GMFCS level III). CONCLUSIONS The prevalence of obesity in ambulatory children with cerebral palsy has risen over the last decade from 7.7% to 16.5%, an increase that is similar to that seen in the general pediatric population in the United States. This finding may have a major impact on the general health and functional abilities of these children as they reach adult life.