Gastrocnemius medialis and Achilles tendon properties do not differ between children with unilateral or bilateral spastic cerebral palsy.

Spastic cerebral palsy (SCP) is a common neurodevelopmental disorder in children, which can be categorized into unilateral and bilateral subtypes. Most studies examining the muscle-tendon properties of the lower extremities in individuals with SCP do not distinguish between subtypes. However, spastic muscle morphology is an important determinant for its function. Therefore, differences in muscle-tendon pathology might lead to different treatment strategies. The aim of this retrospective study was to investigate the muscle-tendon properties between children with unilateral SCP and those with bilateral SCP. Overall, 33 ambulatory children (15 with unilateral SCP and 18 with bilateral SCP, Gross Motor Function Classification System Level I-III) were included. Ankle joint range of motion, isometric muscle strength, and muscle-tendon properties of the gastrocnemius medialis (GM) muscle-tendon unit (MTU) (e.g., muscle volume, tissue lengthening behavior) were assessed with isokinetic dynamometry, 3D motion capture, and ultrasound, respectively. Independent t-tests or Mann-Whitney tests were used to test for group differences (α = 0.05). Effect sizes (Cohen's d) were also calculated. No significant differences in any assessed parameter were found between children with unilateral SCP and children with bilateral SCP (p > 0.05, d < 0.57). Our findings suggest that the functional and morphological properties of the GM MTU are similarly developed in children with unilateral SCP and children with bilateral SCP. We assume that activity levels might be the decisive factor. Nonetheless, our investigations need be extended by including gait parameters and associated tissue dynamics.

Different gait pattern in adolescence with patellofemoral instability.

BACKGROUND: Patellofemoral instability influences the gait pattern and activity level in adolescents. However, gait biomechanics to cope with recurrent patella instability and its relation to radiological findings has hardly been studied. METHODS: We retrospectively analyzed kinematic and kinetic gait analysis data, magnetic resonance images and X-ray of 32 adolescents with unilateral recurrent patellofemoral instability aged 12 to 18 years. Subjects were assigned to 3 groups based on their sagittal knee moment in the loading response and mid stance phase. Kinematic and kinetic differences among the groups were analyzed using a one-way ANOVA. A multinomial logistic regression model provided a further analysis of the relationship between gait biomechanics and MRI as well as X-ray parameters. FINDINGS: All three groups showed different characteristics of the knee kinematics during loading response and single stance: while the patella-norm-loading group showed a slightly reduced knee flexion (p ã€ˆ0,01), the patella-unloading group kept the knee nearly extended (p < 0,01) and patella-overloading group showed an increased knee flexion (p = 0,01) compared to the other groups. In single stance the patella-overloading group maintained increased knee flexion (p < 0,01) compared to patella-unloading group and patella-norm-loading group. None of the radiological parameters proved to be related to gait patterns. INTERPRETATION: The paper describes different gait coping strategies and their clinical relevance in subjects with patellofemoral instability. However, we did not find any relation of gait biomechanics to skeletal morphology.

Eight weeks of proprioceptive neuromuscular facilitation stretching and static stretching do not affect muscle-tendon properties, muscle strength, and joint function in children with spastic cerebral palsy.

BACKGROUND: While the effect of static stretching for individuals with cerebral palsy is questionable, recent results suggest that the combination with activation seems promising to improve muscle-tendon properties and function. Therefore, this study analyzed the effects of 8-week proprioceptive neuromuscular facilitation stretching on the gastrocnemius medialis muscle-tendon properties, muscle strength, and the ankle joint in children with spastic cerebral palsy in comparison to static stretching. METHODS: Initially, 24 children with spastic cerebral palsy were randomly assigned to a static stretching (10.7 ± 1.8 years) or proprioceptive neuromuscular facilitation stretching group (10.9 ± 2.6 years). Plantar flexors were manually stretched at home for 300 s and âˆ¼ 250-270 s per day four times a week for eight weeks, respectively. Assessments of ankle joint function (e.g., range of motion), muscle-tendon properties, and isometric muscle strength were conducted using 3D motion capture, 2D ultrasound, dynamometry, and electromyography. A mixed analysis of variance was used for the statistical analysis. FINDINGS: Stretching adherence was high in the proprioceptive neuromuscular facilitation stretching (93.1%) and static stretching group (94.4%). No significant changes (p > 0.05) were observed in ankle joint function, muscle-tendon properties, and isometric muscle strength after both interventions. Moreover, no differences (p > 0.05) were found between the stretching techniques. INTERPRETATION: The findings support the idea that manual stretching (neither proprioceptive neuromuscular facilitation stretching nor static stretching) performed in isolation for eight weeks may not be appropriate to evoke significant changes in muscle-tendon properties, voluntary muscle strength, or joint function in children with spastic cerebral palsy. CLINICAL TRIAL REGISTRATION NUMBER: NCT04570358.

Gait Pathology in Subjects with Patellofemoral Instability: A Systematic Review.

Identifying potential gait deviations in patellofemoral instability (PI) can help with the development of effective rehabilitation strategies. The purpose of this systematic review was to examine whether there are specific gait alterations in subjects with PI. The present review followed the PRISMA guidelines and was initially registered at PROSPERO (CRD42021236765). The literature search was carried out in the databases of PubMed, the Cochrane library, Web of Science, ClinicalTrials.gov, and Medline. The search strategy resulted in the identification of seven relevant publications. Subjects with PI show decreased walking speed, stride length, and cadence. Some studies reported changes not only in knee kinematics and kinetics but also in hip and ankle kinematics and kinetics. There is evidence that most subjects with PI walk with a quadriceps avoidance gait and show increased genu valgum posture, but there is still great variability in the coping responses within individuals with PI. The discrepancy among the study results might underpin the fact that PI is a multifactorial problem, and subjects cope with the different underlying morphological as well as functional deficits using a variety of gait strategies, which makes the interpretation and understanding of the gait of subjects with PI a clinically challenging task.

Acute Effects of Static and Proprioceptive Neuromuscular Facilitation Stretching of the Plantar Flexors on Ankle Range of Motion and Muscle-Tendon Behavior in Children with Spastic Cerebral Palsy-A Randomized Clinical Trial.

Stretching is considered a clinically effective way to prevent muscle contracture development in children with spastic cerebral palsy (CP). Therefore, in this study, we assessed the effects of a single session of proprioceptive neuromuscular facilitation (PNF) or static stretching (SS) on ankle joint range of motion (RoM) and gastrocnemius muscle-tendon behavior in children with CP. During the SS (n = 8), the ankle joint was held in maximum dorsiflexion (30 s). During the PNF stretching (n = 10), an isometric contraction (3-5 s) was performed, followed by stretching (~25 s). Ten stretches were applied in total. We collected data via dynamometry, 3D motion capture, 2D ultrasound, and electromyography, before and after the stretching sessions. A mixed ANOVA was used for the statistical analysis. Both ankle RoM and maximum dorsiflexion increased over time (F(1,16) = 7.261, p < 0.05, η² = 0.312; and F(1,16) = 4.900, p < 0.05, η² = 0.234, respectively), without any difference between groups. An interaction effect (F(1,12) = 4.768, p = 0.05, η² = 0.284) was observed for muscle-tendon unit elongation (PNF: -8.8%; SS: +14.6%). These findings suggest a positive acute effect of stretching on ankle function. However, SS acutely increased muscle-tendon unit elongation, while this decreased after PNF stretching, indicating different effects on the spastic muscles. Whether PNF stretching has the potential to cause positive alterations in individuals with CP should be elucidated in future studies.

Validity and reliability of a novel 3D ultrasound approach to assess static lengths and the lengthening behavior of the gastrocnemius medialis muscle and the Achilles tendon in vivo.

PURPOSE: Human muscle-tendon units (MTUs) are highly plastic and undergo changes in response to specific diseases and disorders. To investigate the pathological changes and the effects of therapeutic treatments, the use of valid and reliable examination methods is of crucial importance. Therefore, in this study, a simple 3D ultrasound approach was developed and evaluated with regard to: (1) its validity in comparison to magnetic resonance imaging (MRI) for the assessment of the gastrocnemius medialis (GM) MTU, muscle belly, and Achilles tendon lengths; and (2) its reliability for static and dynamic length measurements. METHODS: Sixteen participants were included in the study. To evaluate the validity and reliability of the novel 3D ultrasound approach, two ultrasound measurement sessions and one MRI assessment were performed. By combining 2D ultrasound and 3D motion capture, the tissue lengths were assessed at a fixed ankle joint position and compared to the MRI measurements using Bland-Altman plots. The intra-rater and inter-rater reliability for the static and dynamic length assessments was determined using the coefficient of variation, standard error of measurement (SEM), minimal detectable change (MDC95), and intraclass correlation coefficient (ICC). RESULTS: The 3D ultrasound approach slightly underestimated the length when compared with MRI by 0.7%, 1.5%, and 1.1% for the GM muscle belly, Achilles tendon, and MTU, respectively. The approach showed excellent intra-rater as well as inter-rater reliability, with high ICC (≥ 0.94), small SEM (≤ 1.3 mm), and good MDC95 (≤ 3.6 mm) values, with even better reliability found for the static length measurements. CONCLUSION: The proposed 3D ultrasound approach was found to be valid and reliable for the assessment of the GM MTU, muscle belly, and Achilles tendon lengths, as well as the tissue lengthening behavior, confirming its potential as a useful tool for investigating the effects of training interventions or therapeutic treatments (e.g., surgery or conservative treatments such as stretching and orthotics). LEVEL OF EVIDENCE: Level II.

Kinematic and Kinetic Gait Parameters Can Distinguish between Idiopathic and Neurologic Toe-Walking.

The differentiation between mild forms of toe-walking (equinus) in cerebral palsy (CP) and idiopathic toe-walking (ITW) is often clinically challenging. This study aims to define kinematic and kinetic parameters using 3D gait analysis to facilitate and secure the diagnosis of "idiopathic toe-walking". We conducted a retrospective controlled stratified cohort study. 12 toe-walking subjects per group diagnosed as ITW or CP were included and stratified according to age, gender and maximal dorsiflexion in stance. We collected kinematic and kinetic data using a three-dimensional optical motion analysis system with integrated floor force plates. Pairwise comparison between ITW and CP gait data was performed, and discriminant factor analysis was conducted. Both groups were compared with typically developing peers (TD). We found kinematic and kinetic parameters having a high discriminatory power and sensitivity to distinguish between ITW and CP groups (e.g., knee angle at initial contact (91% sensitivity, 73% specificity) and foot progression angle at midstance (82% sensitivity, 73% specificity)). The strength of this study is a high discriminatory power between ITW and CP toe-walking groups. Described kinematic parameters are easy to examine even without high-tech equipment; therefore, it is directly transferable to everyday praxis.