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

Mechanical Efficiency of Real Machines01:14

Mechanical Efficiency of Real Machines

905
The mechanical efficiency of a machine is a fundamental concept that describes how effectively a machine can convert input work into output work. According to this concept, the efficiency of a machine is equal to the ratio of the output work to the input work. An ideal machine, meaning a machine that has no energy losses, has an efficiency of one. This implies that the input work and the output work are equal.
However, in reality, no machine can be truly ideal, and all of them experience some...
905

You might also read

Related Articles

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

Sort by
Same author

Diagnostic approaches and clinical challenges of imaging in peripheral nerve tumors: data from the multicenter Peripheral Nerve Tumor Registry.

Journal of neurosurgery·2026
Same author

Improving lives: Health-related quality of life after surgery for traumatic brachial plexus lesions in a single center retrospective study.

Brain & spine·2026
Same author

Association of kynurenine metabolites with cognitive and psychological symptoms in post COVID-19 condition: A case-control study.

Journal of psychosomatic research·2026
Same author

One-year outcomes of bioresorbable magnesium scaffold implantation in complex coronary lesions.

Frontiers in cardiovascular medicine·2026
Same author

Impact of ABO Blood Group on Vascular Complications and on Clinical and Functional Outcome After Aneurysmal Subarachnoid Hemorrhage.

Neurology international·2026
Same author

PSA persistence in the PSMA PET era: reassessing a risk factor after radical prostatectomy.

Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology·2026

Related Experiment Video

Updated: Oct 4, 2025

Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity
08:40

Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity

Published on: June 12, 2019

7.6K

Initial Evaluation of the Concept-2 Rowing Ergometer's Accuracy Using a Motorized Test Rig.

Gunnar Treff1,2, Lennart Mentz1, Benjamin Mayer3

  • 1Division of Sports- and Rehabilitation Medicine, Ulm University, Ulm, Germany.

Frontiers in Sports and Active Living
|February 11, 2022
PubMed
Summary

The Concept 2 rowing ergometer

Keywords:
automated testinghome-based trainingindoor rowingpower outputvalidity

More Related Videos

Determining and Controlling External Power Output During Regular Handrim Wheelchair Propulsion
08:55

Determining and Controlling External Power Output During Regular Handrim Wheelchair Propulsion

Published on: February 5, 2020

7.6K
A Method for Evaluating Timeliness and Accuracy of Volitional Motor Responses to Vibrotactile Stimuli
07:28

A Method for Evaluating Timeliness and Accuracy of Volitional Motor Responses to Vibrotactile Stimuli

Published on: August 2, 2016

7.4K

Related Experiment Videos

Last Updated: Oct 4, 2025

Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity
08:40

Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity

Published on: June 12, 2019

7.6K
Determining and Controlling External Power Output During Regular Handrim Wheelchair Propulsion
08:55

Determining and Controlling External Power Output During Regular Handrim Wheelchair Propulsion

Published on: February 5, 2020

7.6K
A Method for Evaluating Timeliness and Accuracy of Volitional Motor Responses to Vibrotactile Stimuli
07:28

A Method for Evaluating Timeliness and Accuracy of Volitional Motor Responses to Vibrotactile Stimuli

Published on: August 2, 2016

7.4K

Area of Science:

  • Sports Science
  • Biomechanics
  • Ergometry

Background:

  • The Concept 2 (C2) rowing ergometer is a widely used device for training and performance assessment.
  • Previous research indicated potential underestimation of power output, linked to stroke variability.

Purpose of the Study:

  • To quantify the accuracy of the C2 ergometer.
  • To assess the influence of rowing stroke variables (shape, force, rate) on C2 accuracy.
  • To exclude biological variability using a motorized test rig.

Main Methods:

  • Utilized a unique motorized test rig for rowing ergometers.
  • Assessed accuracy by comparing C2 power output to a reference system.
  • Simulated both steady and unsteady rowing conditions, manipulating stroke variables.

Main Results:

  • During steady rowing, C2 underestimation ranged from 2.9-4.3%.
  • Stroke rate significantly impacted accuracy (22-28 min⁻¹), while stroke shape did not.
  • Unsteady rowing showed similar mean differences but up to 18-fold increased random error; initial strokes were underestimated by 10-70%.

Conclusions:

  • C2 ergometer accuracy is dependent on the number of strokes considered, ranging from 0.2-1.9% after sufficient flywheel acceleration.
  • Inaccuracy increases with uneven rowing; higher stroke rates and consistent rowing improve readings.
  • External reference systems are recommended for scientific and high-performance assessments, particularly for short tests.