Lower extremity isometric joint torque in children with juvenile chronic arthritis.

OBJECTIVE: To determine the intratester reliability of joint torque testing with a hand-held dynamometer (HHD) during contractions of four major lower extremity muscles in children with juvenile chronic arthritis (JCA) and to compare results for children with JCA to results for children without disability. METHODS: Eleven children with JCA and 14 children with normal musculoskeletal function were tested with a HHD using isometric muscle contractions of the right quadriceps, hamstrings, tibialis anterior and triceps surae. RESULTS: Intratester reliability values exceeded the 0.92 level, regardless of the number of trials, for all motions tested. Statistically lower joint torque values were found in a subgroup of children with JCA for contractions of the tibialis anterior (p=0.003) and triceps surae (p=0.05) muscles. CONCLUSIONS: HHD offers a reliable means of testing the joint torque generated with contraction of these lower extremity muscles in children with JCA. Findings in children with JCA compared to children without disability agree with previous reports concerning quadriceps muscle function, but also point to concerns for muscles associated with generating ankle joint torque.

A guide for use and interpretation of kinesiologic electromyographic data.

Physical therapists are among the most common users of electromyography as a method for understanding function and dysfunction of the neuromuscular system. However, there is no collection of references or a source that provides an overview or synthesis of information that serves to guide either the user or the consumer of electromyography and the data derived. Thus, the purpose of this article is to present a guide, accompanied by an inclusive reference list, for the use and interpretation of kinesiologic electromyographic data. The guide is divided into 4 major sections: collecting, managing, normalizing, and analyzing kinesiologic electromyographic data. In the first of these sections, the issues affecting data collection with both indwelling and surface electrodes are discussed. In the second section, data management through alternative forms of data processing is addressed. In the third section, various reasons and procedures for data normalization are discussed. The last section reviews qualitative descriptors once used as the only means of analyzing data, then focuses on more quantitative procedures that predominate today. The guide is intended as a tool for students, educators, clinicians, and beginning researchers who use and interpret kinesiologic electromyographic data. Modifications will likely be needed as alternative forms of collecting, managing, normalizing, and analyzing electromyographic data are proposed, used in various settings, and reported in the literature.

Comparison of different systems to classify the neurological level of lesion in patients with myelomeningocele.

In 73 patients with myelomeningocele (mean 17.2 years, range 5 to 40 years) the classification of level of lesion was studied according to six commonly used classification systems and to the ambulation groups of Hoffer. The distribution of the patients into classes of thoracic-level lesions was the same for four classification systems in 10 patients and for two classification systems into categories of level L3 in 14 patients. For the other patients discrepancies occurred between systems for lesions of level L3 and downward. None of the patients was consistently categorized in the functional ambulation groups of Hoffer using all classification systems. The results show that it is not possible to compare neurological lesion levels classified according to the different systems described in this study and consequently that the distribution into the functional ambulation groups of Hoffer varies. To enhance communication and facilitate comparing the results of treatment we suggest using some basic criteria for patient documentation.

Kinematic and electromyographic characteristics of children with cerebral palsy who exhibit genu recurvatum.

The objective of this article was to determine, using selected computerized gait analysis procedures, whether variation exists in the gait patterns of children with cerebral palsy who exhibit genu recurvatum. This descriptive study compared differences in kinematic, temporal-distance, and electromyographic (EMG) variables between two groups of children with cerebral palsy who exhibited genu recurvatum and age-matched controls. The setting was a motion analysis laboratory. Six children with cerebral palsy who showed genu recurvatum and a control group of four normal children participated in this study. Main outcome measures were hip-knee angle-angle diagrams, knee phase plane plots, knee angle versus time diagrams, stride length, cadence, single-limb support, and EMG data. Through use of hip-knee angle-angle diagrams, knee phase plane plots, and knee angle versus time diagrams, distinctive kinematic patterns emerged, allowing for grouping of subjects. Kinematic measures of knee angle at foot-floor contact and knee angle at greatest extension provided further support for the groups created, as did temporal-distance measures of stride length, cadence, and single-limb support. Analysis of variance procedures for the EMG data showed selected time points in the gait cycle during which differences between the groups were observed. Because differences in kinematic, temporal-distance, and EMG variables existed in this study to warrant grouping into two categories, physical therapists and orthopedic surgeons may need to vary the treatments they introduce dependent on the nature of the child's gait pattern.

Chiari pelvic osteotomy in cerebral palsy.

Hip subluxation and dislocation in patients with cerebral palsy are challenging problems. The Chiari pelvic osteotomy has been commonly recommended as a technique for hip stabilization when acetabular dysplasia is present. We evaluated the results of Chiari osteotomy without concomitant femoral osteotomy in 24 hips in 23 patients with an average follow-up of > 7 years. Evaluation consisted of a pain and function questionnaire, chart review, physical examination, and review of serial radiographs. At final follow-up, 19 of 24 (79%) of the hips were painless, and 21 of 24 hips (88%) permitted unlimited sitting. Seven of 24 (29%) of hips, however, had a migration index of > or = 30%. Painful hips were associated with a greater migration index preoperatively, at 1 year postoperatively, and at final follow-up, and a greater height of the osteotomy above the edge of the acetabulum. Deterioration in the migration index (resubluxation) occurred largely in the first year postoperatively. Alternative acetabular procedures, simultaneous femoral osteotomies, or both may improve on these results. Long-term follow-up studies are necessary to compare the results of different treatments for spastic hip subluxation and dislocation to determine optimal treatment.

A study of various normalization procedures for within day electromyographic data.

Normalization of electromyographic (EMG) data has been described in the scientific literature as crucial for comparisons between subjects and between muscles. The reference value used in the normalization equation has, however, varied across reports. Comparison between studies could be facilitated by use of a common value. We propose the best way to select the common value is through a reliability approach. Accordingly, the purpose of this study was to identify which of three EMG normalization values provided the most reproducible data set. The gastrocnemius EMG results from 20 normal persons and 20 individuals with anterior cruciate deficiency who were participating in a larger study were normalized to a maximum voluntary isometric contraction (MVIC) EMG, peak dynamic EMG, and mean dynamic EMG. Values were then subjected to evaluation using four statistical measures: inter and intrasubject coefficients of variation (CV), variance ratio (VR), and intraclass correlation coefficient (ICC). The CV measures, while not being reflective of reliability were included for comprehensive consideration in view of other literature. The intersubject CV which measures group variability and the intrasubject CV which measures precision were lower for the dynamic conditions, however, the VR and ICC suggested reproducibility was best with EMG from the MVIC. Given that other studies have advocated normalizing EMG by taking data from the dynamic event, reconsideration may be warranted if high reproducibility is desired. Interpretations of the findings given the population, muscle and condition studied are discussed.

Orthotic devices for ambulation in children with cerebral palsy and myelomeningocele.

Children with cerebral palsy and children with myelomeningocele frequently require orthotic devices for standing and walking. The purpose of this article is to review the literature on orthotic devices for walking, present principles of lower-extremity orthoses, discuss designs of orthoses, and consider criteria for selecting orthotic devices. Although discussion of the devices is specific to children with myelomeningocele and to children with cerebral palsy, the orthoses can be used with children having other disabilities. The information presented should be of value to clinicians, educators, and researchers interested in reviewing orthotic applications for children with disabilities.