Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Work and Energy for Variable Forces01:10

Work and Energy for Variable Forces

5.8K
When an object is acted upon by a variable force, the amount of work done and the change in energy of the object can be more complex to calculate compared to when a constant force is applied. Work is the product of force and displacement, while energy is the capacity of a system to do work. When a constant force is applied to an object, the work done can be calculated as the product of the force and the distance moved in the direction of the force. However, when a variable force is applied, the...
5.8K
Fluid Pressure over Flat Plate of Variable Width01:02

Fluid Pressure over Flat Plate of Variable Width

2.1K
When a flat plate is submerged in a fluid, the fluid exerts pressure on the plate. This pressure can lead to many different phenomena, including drag and buoyancy. To understand the behavior of the fluid over a flat plate of variable width, it is essential to analyze the distribution of the pressure exerted.
The pressure distribution on the plate can be calculated by determining the force that acts on a differential area strip of the plate. Thus, the magnitude of the force is equal to the...
2.1K
Diagnosing Acidosis and Alkalosis01:24

Diagnosing Acidosis and Alkalosis

1.2K
Diagnosing acid-base imbalances involves systematically analyzing arterial blood samples, focusing on three key measurements: pH, bicarbonate (HCO3−) concentration, and carbon dioxide partial pressure (PCO2). This analysis follows a four-step process that helps identify the imbalance's underlying cause and nature.
First, the pH level is assessed to determine whether the blood pH is normal (7.35–7.45), low (acidosis), or high (alkalosis).
Next, the PCO2  and...
1.2K
Knee Joint01:23

Knee Joint

3.2K
The knee joint is the most complicated joint in the body. It consists of three articulations– two tibiofemoral and one patellofemoral. As is characteristic of synovial joints, the knee joint has a thin articular capsule that partially surrounds this joint cavity. Additionally, several ligaments, muscles, and cartilaginous structures support the movement of the knee.
A total of seven ligaments support the knee joint. The patellar ligament, which is also attached to the quadriceps femoris...
3.2K
Variability: Analysis01:11

Variability: Analysis

511
Measures of variability are statistical metrics that reveal the dispersion pattern within a dataset. They are pivotal in biostatistics, providing insights into the heterogeneity within health and biological data. Variability signifies the degree to which data points diverge from one another, helping researchers understand the potential range of values and associated uncertainty within the data.
The range is a simple measure of variability, indicating the difference between the highest and...
511
Random Variables01:09

Random Variables

17.8K
A random variable is a single numerical value that indicates the outcome of a procedure. The concept of random variables is fundamental to the probability theory and was introduced by a Russian mathematician, Pafnuty Chebyshev, in the mid-nineteenth century.
Uppercase letters such as X or Y denote a random variable. Lowercase letters like x or y denote the value of a random variable. If X is a random variable, then X is written in words, and x is given as a number.
For example, let X = the...
17.8K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Global Analysis the Potential Medicinal Substances of Shuangxia Decoction and the Process <i>In Vivo</i> via Mass Spectrometry Technology.

Frontiers in pharmacology·2021
Same author

Relationship Between Rheumatoid Arthritis and Pulmonary Function Measures on Spirometry in the UK Biobank.

Arthritis & rheumatology (Hoboken, N.J.)·2021
Same author

Incorporating Guanidinium as Perovskitizer-Cation of Two-Dimensional Metal Halide for Crystal-Array Photodetectors.

Chemistry, an Asian journal·2021
Same author

Guided suturing technique for midface lift through minimal temporal incision.

Journal of plastic, reconstructive & aesthetic surgery : JPRAS·2021
Same author

Drug-induced liver injury: Oltipraz and C2-ceramide intervene HNF-1α/GSTA1 expression via JNK signaling pathway.

Journal of applied toxicology : JAT·2021
Same author

Regulation of MRP4 Expression by circHIPK3 via Sponging miR-124-3p/miR-4524-5p in Hepatocellular Carcinoma.

Biomedicines·2021

Related Experiment Video

Updated: Feb 4, 2026

In vivo Measurement of Knee Extensor Muscle Function in Mice
08:29

In vivo Measurement of Knee Extensor Muscle Function in Mice

Published on: March 4, 2021

5.6K

Can Knee Extensor Loading Deficits Be Diagnosed Using Variables from Force Plates during Squats Post-ACLr?

Jiaqi Wang1, Lori Michener, Kathryn Havens

  • 1Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA.

Medicine and Science in Sports and Exercise
|February 3, 2026
PubMed
Summary

Estimating knee extensor mechanism (KEM) deficits after ACLr surgery is more accurate using combined force plate and 2D position data than vertical ground reaction force alone. The Vector Approach demonstrated the highest diagnostic accuracy for identifying limb deficits.

Keywords:
ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTIONCENTER OF PRESSURECLINICAL DETECTIONGROUND REACTION FORCE VECTORMOMENT ARM

More Related Videos

Gathering Self-Initiated Rat Behavioral Data to Characterize Post-Stroke Deficits
05:08

Gathering Self-Initiated Rat Behavioral Data to Characterize Post-Stroke Deficits

Published on: March 15, 2024

1.6K
Author Spotlight: Assessing the Reliability of Doppler Ultrasound in Measuring Leg Blood Flow
09:18

Author Spotlight: Assessing the Reliability of Doppler Ultrasound in Measuring Leg Blood Flow

Published on: December 15, 2023

3.5K

Related Experiment Videos

Last Updated: Feb 4, 2026

In vivo Measurement of Knee Extensor Muscle Function in Mice
08:29

In vivo Measurement of Knee Extensor Muscle Function in Mice

Published on: March 4, 2021

5.6K
Gathering Self-Initiated Rat Behavioral Data to Characterize Post-Stroke Deficits
05:08

Gathering Self-Initiated Rat Behavioral Data to Characterize Post-Stroke Deficits

Published on: March 15, 2024

1.6K
Author Spotlight: Assessing the Reliability of Doppler Ultrasound in Measuring Leg Blood Flow
09:18

Author Spotlight: Assessing the Reliability of Doppler Ultrasound in Measuring Leg Blood Flow

Published on: December 15, 2023

3.5K

Area of Science:

  • Biomechanics
  • Orthopedics
  • Sports Medicine

Background:

  • Knee extensor mechanism (KEM) deficits are common after anterior cruciate ligament reconstruction (ACLr).
  • Accurate identification of these deficits is crucial for rehabilitation and return to sport.
  • Current assessment methods may not fully capture the complexities of KEM function.

Purpose of the Study:

  • To investigate the accuracy of three methods for estimating KEM deficits using force plate and 2D motion data.
  • To identify individuals with surgical limb KEM deficits during a bilateral squat.
  • To compare the diagnostic accuracy of different estimation approaches against a gold standard.

Main Methods:

  • Forty individuals post-ACLr performed bilateral squats, with kinematic and ground reaction force (GRF) data collected.
  • KEM deficits were calculated using the limb symmetry index (LSI) at peak knee flexion.
  • Three approaches were evaluated: Vertical GRF alone, GRF with center of pressure (COP) position, and a Vector Approach incorporating moment arm calculations.
  • Concurrent validity and diagnostic accuracy (sensitivity and specificity) were assessed against an inverse dynamics gold standard.

Main Results:

  • The Vector Approach demonstrated the highest predictive ability (R² = 0.85) and concurrent validity (ICC(2,k) = 0.96) for estimating KEM deficits.
  • This approach achieved 100% sensitivity and 100% specificity in identifying individuals with deficits (LSI threshold ≥ 0.85).
  • The GRF-COP approach also showed strong predictive ability (R² = 0.74, ICC(2,k) = 0.92) with 94.4% sensitivity and 50% specificity.

Conclusions:

  • Vertical GRF alone is insufficient for accurately detecting KEM deficits post-ACLr.
  • Integrating force plate data with 2D kinematic information (COP position, moment arm) significantly enhances the predictive ability and diagnostic accuracy of KEM deficit assessments.
  • These findings support the development of advanced clinical assessment tools for improved rehabilitation outcomes.