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

Isotonic and Isometric Muscle Contractions01:22

Isotonic and Isometric Muscle Contractions

6.8K
Two primary types of muscle contractions are isotonic and isometric, each serving unique functions and involving distinct mechanisms. Both isotonic and isometric contractions are integral to the body's complex system of movement and stability. Isotonic exercises contribute significantly to functional strength and movement, while isometric contractions are crucial for maintaining posture and joint stability.
Isotonic contractions
Isotonic contractions occur when a muscle changes length while...
6.8K
Kinematic Equations for Rotation01:30

Kinematic Equations for Rotation

770
In mechanics, when one observes a rigid body in rotational motion with constant angular acceleration, it is possible to establish equations for its rotational kinematics. This process resembles how linear kinematics are dealt with in simpler motion studies.
For instance, imagine a point A on a rigid body engaged in circular motion. The translational velocity of this particular point can be calculated by taking the time derivatives of the displacement equation, which essentially measures the...
770
Rotation of Asymmetric Top01:11

Rotation of Asymmetric Top

1.5K
By definition, a spherically symmetric body has the same moment of inertia about any axis passing through its center of mass. This situation changes if there is no spherical symmetry. Since most rigid bodies are not spherically symmetric, these require special treatment.
The relationship between the angular momentum of any rigid body and its angular velocity, both of which are vectors, involves the moment of inertia. The moment of inertia is a scalar quantity only for spherically symmetric...
1.5K
Rotational Motion about a Fixed Axis01:26

Rotational Motion about a Fixed Axis

1.3K
A rigid body's rotation around a fixed axis makes every point within it trace a circular path around a specific line or point. The term given to this type of spinning is defined by the angular position, symbolized by the angle θ. This angle is gauged from a static reference line to the revolving object. From this angular position, any variation is referred to as angular displacement, denoted by dθ. The extent of this displacement can be calculated in degrees, radians, or...
1.3K
Rotation with Constant Angular Acceleration - I01:37

Rotation with Constant Angular Acceleration - I

8.1K
If angular acceleration is constant, then we can simplify equations of rotational kinematics, similar to the equations of linear kinematics. This simplified set of equations can be used to describe many applications in physics and engineering where the angular acceleration of a system is constant.
Using our intuition, we can begin to see how rotational quantities such as angular displacement, angular velocity, angular acceleration, and time are related to one another. For example, if a flywheel...
8.1K
Rotation with Constant Angular Acceleration - II01:16

Rotation with Constant Angular Acceleration - II

7.0K
Kinematics is the description of motion. The kinematics of rotational motion discusses the relationships between rotation angle, angular velocity, angular acceleration, and time. One can describe many things with great precision using kinematics, but kinematics does not consider causes. For example, a large angular acceleration describes a very rapid change in angular velocity without any consideration of its cause. Thus, rotational kinematics does not represent the laws of nature.
The first...
7.0K

You might also read

Related Articles

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

Sort by
Same author

The Impact of a Single Session of Sprint Interval Training (SIT) on Pain Pressure Threshold (PPT) in Healthy Adults.

Sports (Basel, Switzerland)·2026
Same author

Optimising exercise prescription for cancer-related fatigue, lean mass, physical function and muscle strength in women with breast cancer: a systematic review with dose-response network meta-analysis.

British journal of sports medicine·2026
Same author

Dynamic multi and single joint strength and vertical jump performance in amateur athletes who have returned to sport following anterior cruciate ligament reconstruction.

The Journal of sports medicine and physical fitness·2026
Same author

Response to Comment on "Periodizing Exercise Medicine Prescription for Patients with Cancer: A Narrative Opinion".

Sports medicine (Auckland, N.Z.)·2026
Same author

Seasonal Associations Between Isometric Strength and Dynamic Performance in Elite Youth Soccer Players.

International journal of sports physiology and performance·2026
Same author

Comparative effectiveness of physical therapy interventions in adults with rotator cuff tendinopathy: a systematic review and network meta-analysis.

British journal of sports medicine·2026

Related Experiment Video

Updated: Jan 22, 2026

Arthroscopic Management of Massive Irreparable Rotator Cuff Tears: Whole Rotator Cable Reconstruction Using Proximal Biceps Tendon Autograft
07:22

Arthroscopic Management of Massive Irreparable Rotator Cuff Tears: Whole Rotator Cable Reconstruction Using Proximal Biceps Tendon Autograft

Published on: June 6, 2025

581

Assessment of Rotator Cuff External Rotation: Isometric vs. Isotonic Testing Modes.

Luca Maestroni1,2, Filippo Beretta3, Fabio Civera1

  • 1ReAct, Via Madonna della Neve, 24, 24121 Bergamo, Italy.

Journal of Functional Morphology and Kinesiology
|January 21, 2026
PubMed
Summary

Shoulder external rotation strength tests, both isometric and isotonic, demonstrate excellent reliability in healthy adults. While isometric tests showed gender differences, isotonic tests did not, indicating they capture different aspects of shoulder strength.

Keywords:
assessmentperformancerepetition maximumrotator cuff

More Related Videos

Development of a Rabbit Chronic-Like Rotator Cuff Injury Model for Study of Fibrosis and Muscular Fatty Degeneration
05:20

Development of a Rabbit Chronic-Like Rotator Cuff Injury Model for Study of Fibrosis and Muscular Fatty Degeneration

Published on: March 31, 2023

1.7K
Donor Posterior Atrial Flap Rotation for Left Atrial Cuff Reconstruction in Lung Transplantation
07:28

Donor Posterior Atrial Flap Rotation for Left Atrial Cuff Reconstruction in Lung Transplantation

Published on: October 11, 2024

717

Related Experiment Videos

Last Updated: Jan 22, 2026

Arthroscopic Management of Massive Irreparable Rotator Cuff Tears: Whole Rotator Cable Reconstruction Using Proximal Biceps Tendon Autograft
07:22

Arthroscopic Management of Massive Irreparable Rotator Cuff Tears: Whole Rotator Cable Reconstruction Using Proximal Biceps Tendon Autograft

Published on: June 6, 2025

581
Development of a Rabbit Chronic-Like Rotator Cuff Injury Model for Study of Fibrosis and Muscular Fatty Degeneration
05:20

Development of a Rabbit Chronic-Like Rotator Cuff Injury Model for Study of Fibrosis and Muscular Fatty Degeneration

Published on: March 31, 2023

1.7K
Donor Posterior Atrial Flap Rotation for Left Atrial Cuff Reconstruction in Lung Transplantation
07:28

Donor Posterior Atrial Flap Rotation for Left Atrial Cuff Reconstruction in Lung Transplantation

Published on: October 11, 2024

717

Area of Science:

  • Orthopedics
  • Sports Medicine
  • Biomechanics

Background:

  • Shoulder external rotation strength is crucial for various athletic and daily activities.
  • Reliable assessment methods are needed to evaluate shoulder strength accurately.
  • Existing research has not fully compared isometric and isotonic strength tests for shoulder external rotation.

Purpose of the Study:

  • To determine the intra-session reliability of isometric and isotonic shoulder external rotation (ER) strength tests.
  • To compare the outcomes and identify potential differences between these testing methods.
  • To establish normative data for 5 repetition maximum (RM) ER strength in healthy adults.

Main Methods:

  • Thirty-eight healthy participants (19 males, 19 females) underwent isometric (Prone and Standing ER) and isotonic (Seated 5 RM ER) strength testing.
  • Intra-session reliability was assessed using the coefficient of variation (CV) and intraclass correlation coefficient (ICC).
  • Linear mixed models and regression analyses were employed to examine sex, dominance effects, and associations between tests.

Main Results:

  • All tested shoulder ER strength measures exhibited excellent reliability (CV: 1.9–3.1%; ICC: 0.970–0.994).
  • Males demonstrated significantly higher isometric ER strength than females (Prone: 3.8%, Standing: 2.7%).
  • Prone isometric strength was a significant predictor of Seated 5 RM ER strength, explaining 52.4% of the variance.

Conclusions:

  • Isometric and isotonic shoulder ER strength tests are highly reliable in healthy adults.
  • Isometric measures do not fully encompass the strength assessed by isotonic tests.
  • While males excel in isometric ER strength, no significant gender difference was found in 5 RM isotonic ER strength.