Effect of posterior cruciate ligament creep on muscular co-activation around knee: a pilot study.

J Electromyogr Kinesiol

Biomechanics Laboratory, College of Physical Education, Shandong Normal University, 88 Wenhua East Road, Jinan, Shandong 250014, China.

Published: April 2014

The effect of posterior cruciate ligament (PCL) on muscle co-activation (MCO) is not known though MCO has been extensively studied. The purpose of the study was to investigate the effect of PCL creep on MCO and on joint moment around the knee. Twelve males and twelve females volunteered for this study. PCL creep was estimated via tibial posterior displacement which was elicited by a 20kg dumbbell hanged on horizontal shank near patella for 10min. Electromyography activity from both rectus femoris and biceps femoris as well as muscle strength on the right thigh was recorded synchronically during knee isokinetic flexion-extension performance in speed of 60deg/s as well as 120deg/s on a dynamometer before and after PCL creep. A one-way ANOVA with repeated measures was used to evaluate the effect of creep, gender and speed. The results showed that significant tibial posterior displacement was found (p=0.01) in both male and female groups. No significant increase of joint moment was found in flexion as well as in extension phase in both female and male groups. There was a significant effect of speed (p=0.036) on joint moment in extension phase. Co-activation index (CI) decreased significantly (p=0.049) in extension phase with a significant effect of gender (p⩽0.001). It was concluded that creep developed in PCL due to static posterior load on the proximal tibia could significantly elicit the increase of the activation of agonist muscles but with no compensation from the antagonist in flexion as well as in extension phase. The creep significantly elicited the decrease of the antagonist-agonist CI in extension phase. MCO in females was reduced significantly in extension phase. It was suggested that PCL creep might be one of risk factors to the knee injury in sports activity.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jelekin.2014.01.005DOI Listing

Publication Analysis

Top Keywords

extension phase
24
pcl creep
16
joint moment
12
posterior cruciate
8
cruciate ligament
8
creep
8
tibial posterior
8
posterior displacement
8
flexion well
8
well extension
8

Similar Publications

Pervasive Games for Sexual Health Promotion: Scoping Literature Review.

JMIR Serious Games

January 2025

Department of Interactive Visualization and Virtual Reality, Faculty of Engineering, University of Talca, Talca, Chile.

Background: Serious games play a fundamental role in promoting safe sexual behaviors. This medium has great potential for promoting healthy behaviors that prevent potential risk factors, such as sexually transmitted infections, and promote adherence to sexual health treatments, such as antiretroviral therapy. The ubiquity of mobile devices enhances access to such tools, increasing the effectiveness of video games as agents of change.

View Article and Find Full Text PDF

Ocrelizumab dose selection for treatment of pediatric relapsing-remitting multiple sclerosis: results of the OPERETTA I study.

J Neurol

January 2025

Division of Child Neurology, Children's Hospital of Philadelphia, Departments of Neurology and Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Background: The presented study identified the appropriate ocrelizumab dosing regimen for patients with pediatric-onset multiple sclerosis (POMS).

Methods: Patients with POMS aged 10-17 years were enrolled into cohort 1 (body weight [BW] < 40 kg, ocrelizumab 300 mg) and cohort 2 (BW ≥ 40 kg, ocrelizumab 600 mg) during a 24-week dose-exploration period (DEP), followed by an optional ocrelizumab (given every 24 weeks) extension period.

Primary Endpoints: pharmacokinetics, pharmacodynamics (CD19 B-cell count); secondary endpoint: safety; exploratory endpoints: MRI activity, protocol-defined relapses, Expanded Disability Status Scale (EDSS) score change.

View Article and Find Full Text PDF

Background: Acute hepatic porphyria (AHP) is characterized by debilitating and potentially life-threatening neurovisceral attacks, possible chronic symptoms, and long-term complications. In a phase 1/2 open-label extension (OLE) study and the phase 3 ENVISION study, givosiran led to sustained improvement in annualized attack rate and quality of life (QOL) measures. To capture the patient experience of symptoms and impacts of AHP, and any changes experienced during treatment with givosiran, qualitative interviews were conducted with study participants.

View Article and Find Full Text PDF

As the extension of the egg-laying cycle, heightened energy and lipid metabolism cause excessive lipid accumulation, resulting in rapid decline in laying performance during the late laying period. Bile acids (BAs), synthesized from cholesterol in the liver, are potent metabolic and immune signaling molecules involved in lipid metabolism and the regulation of energy homeostasis. However, under different dietary protein levels, the role of BAs on hepatic lipid metabolism of laying hens at the late phase remains unclear.

View Article and Find Full Text PDF

Monoclonal antibodies (mAbs) are critical components in the therapeutic landscape, but their dosing strategies often evolve post-approval as new data emerge. This review evaluates post-marketing label changes in dosing information for FDA-approved mAbs from January 2015 to September 2024, with a focus on both initial and extended indications. We systematically analyzed dosing modifications, categorizing them into six predefined groups: Dose increases or decreases, inclusion of new patient populations by body weight or age, shifts from body weight-based dosing to fixed regimens, and adjustments in infusion rates.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!