Contribution of Different Impairments to Restricted Knee Flexion during Gait in Individuals with Cerebral Palsy.

The coexistence of overlapping impairments modulates the knee pattern in the swing phase of walking in children with cerebral palsy (CP). The impact and contribution of each impairment to the reduction of knee range-of-motion is unknown. The aim of the study was to establish the gradation of the impact of individual coexisting impairments on the knee flexion range-of-motion.

The popliteal angle tests in patients with cerebral palsy.

The aims were to determine during the popliteal angle (PA) tests whether particular knee muscles are activated and whether the position of pelvis affects the level of muscles activation. Twenty-two patients with cerebral palsy were recruited (age: 14±4.94 years).

Validation of Manual Muscle Testing (MMT) in children and adolescents with cerebral palsy.

Background: Weakness is a major impairment in many movement disorders, including cerebral palsy (CP), which presents as a decrease in muscle strength. Manual muscle testing (MMT) is very popular in clinical practice, however it has many limitations.

Objective: (1) Whether maximum voluntary contraction (MVC) measures differ across clinical MMT groups; (2) Whether an association exists between clinical MMT score groups and instrumental MVC measures.

Assessment of selective motor control in clinical Gillette's test using electromyography.

Background: Selective motor control (SMC), the ability to isolate selected muscle activation during a functional task, is often impaired. Gillette's SMC scale is commonly used to classify the impairment level; however it may not be sensitive to muscle coactivation.

Aim: To characterize differences in muscle activation levels and coactivation incidence in Gillette's SMC grade levels.

The role of exaggerated patellar tendon reflex in knee joint position sense in patients with cerebral palsy.

The aim of this pilot study was to determine if exaggerated patellar tendon jerk affects knee joint position sense (JPS) in cerebral palsy (CP) patients, by comparing JPS of the knee between participants with normal and exaggerated reflexes. The thresholds for reflex classification were based upon the data from able-bodied volunteers. JPS was measured as the ability of a subject (with eyes closed) to replicate a knee joint position demonstrated by an examiner.

Knee joint angular velocities and accelerations during the patellar tendon jerk.

Tendon jerk (TJ) is one of the most commonly used clinical tests in differential diagnosis of human motor disorders. There remains some ambiguity in the physiological interpretation of the test, especially with respect to its association to the functional status of patients. The TJ test inputs a non-physiological stimuli, but it is unclear to what degree the kinematics generated during the TJ test exceed the ranges that muscles encounter in activities of daily living (ADLs).

Knee resistance during passive stretch in patients with hypertonia.

The aims of the study were to determine by a portable method (1) whether velocity-dependent changes in knee resistance in patients with spastic paresis differ from those in non-disabled subjects, and (2) whether biomechanical measures of resistance can differentiate between neural and other factors that contribute to hypertonia (increased resistance). Biomechanical (hand-hold dynamometer, electrogoniometer) and bioelectrical (EMG) measures of resistance were evaluated under static (slow stretch) and dynamic (fast stretch) conditions in twenty patients with hypertonia and 19 non-disabled subjects. Measures calculated for non-disabled subjects (control limbs) were compared to those calculated for patients (spastic limbs).

The influence of foot position on body dynamics.

During locomotion, the human body exhibits inherent dynamic properties such as mass (M), stiffness (K) and damping (B). During the gait cycle, foot contact with the ground progresses from the heel to the toe. Contact forces between the foot and ground are defined as ground reaction forces (GRF).

Quantifying repeatability of the Wartenberg pendulum test parameters in children with spasticity.

The Wartenberg (pendulum) test is commonly used in a variety of studies involving healthy subjects, patients with CP, stroke patients, and other neurological conditions. There is some evidence that the Wartenberg test may be able to differentiate healthy people from patients with spasticity. The aim of the study was to explore the within-session repeatability of primary outcome measures, i.

Gastrocnemius fascicle length changes with two-joint passive movements.

Predicting muscle fascicle length changes during passive movements may lead to a better understanding of muscle function. The purpose of this study was to experimentally compare fascicle length changes in the gastrocnemius during two-joint passive movements with a previously derived kinematic model based on anatomical measures from a cadaver. The ratio of passive ankle to knee motion was manipulated to generate medial gastrocnemius fascicle elongation and lateral gastrocnemius fascicle shortening.

Visual and proprioceptive feedback improves knee joint position sense.

Joint position sense (JPS), one method to assess proprioception, is the ability to replicate a target limb position. Feedback is commonly used to improve motor performance but it has not been demonstrated to improve JPS. The purpose of this study was to determine if feedback decreases error associated with knee JPS at three movement velocities.

The kinematic consequences of invariant dynamics in children 6-18 years of age.

The effect of limb dynamics on trajectory formation is unclear. The natural frequency of a limb is the major factor in its dynamics. It has previously been shown with an indirect measurement method that the natural frequency of body segments is invariant during human growth from the age of 6 to 18.

Human body shape index based on an experimentally derived model of human growth.

Objectives: To test the assumption of geometrically similar growth by developing experimentally derived models of human body growth during the age interval of 5 to 18 years; to use these derived growth models to establish a new human body shape index (HBSI) based on natural age-related changes in human body shape (HBS); and to compare various metrics of relative body weight (body mass index [BMI], ponderal index [PI], and HBSI) in a sample of 5- to 18-year-old children.

Study Design: Nondisabled Polish children (n = 847) participated in this descriptive study. To model growth, the best fit between body height (H) and body mass (M) was calculated for each sex using the allometric equation M = m(i) H(chi).

Biomechanic characteristics of patients with spastic and dystonic hypertonia in cerebral palsy.

Objective: To determine what biomechanic characteristics of knee joint motion and walking show potential to quantitatively differentiate spasticity and dystonia in cerebral palsy (CP).

Design: Descriptive measurement study.

Setting: University hospital.

Quantitative evaluation of reflex and voluntary activity in children with spasticity.

Objective: To determine whether increased reflexes are related to functional impairment in children with spasticity.

Design: Descriptive measurement study.

Setting: Rehabilitation department in Poland.