Anthropometric Normalization in Inter-Individual Variability of Comprehensive Isokinetic Strength Assessment (PT)

Role of Anthropometric Normalization in Inter-Individual Variability of Comprehensive Isokinetic Strength Assessment in Healthy Women: A Methodological Study

Accurate normalization of peak torque (PT) is critical for comparing muscle strength across individuals of varying body composition. While body weight (BW) is commonly used, body mass index (BMI) may provide a more stable representation of inter-individual variability. The study aims to compare the effects of BW and BMI normalization on inter-individual variability of trunk, hip, and knee muscle strength in healthy female participants.

Study Overview

• Status: Not yet recruiting
• Conditions: Healthy
• Intervention / Treatment: Diagnostic test: effects of BW versus BMI normalization on inter-individual variability of trunk, hip, and knee muscle strength in healthy female

Detailed Description

Accurate normalization of peak torque (PT) is critical for comparing muscle strength across individuals of varying body composition. While body weight (BW) is commonly used, body mass index (BMI) may provide a more stable representation of inter-individual variability. The study aims to compare the effects of BW and BMI normalization on inter-individual variability of trunk, hip, and knee muscle strength in healthy female participants.

Thirty healthy adult females will undergo isokinetic testing of trunk flexors/extensors, hip flexors/extensors/abductors/adductors, and knee flexors/extensors. PT values will be normalized to BW and BMI. Coefficient of variation (CV%) will be calculated for each method to evaluate relative variability.

• Study Type: Observational
• Enrollment (Estimated): 112

Contacts and Locations

• Study Contact: Name: Azza M Abdelmohsen, professor; Phone Number: 01145046304; Email: dr_azzamohammed@yahoo.com
• Study Contact Backup: Name: Azza M, professor; Phone Number: 01145046304; Email: dr_azzamohammed@yahoo.com

Study Locations

• Egypt
  • Giza, Egypt, 12511
    • Faculty of physical therapy, Cairo University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

A total of 112 healthy sedentary females volunteered to participate in the study. Their demographic characteristics including age, weight, height and BMI are illustrated in Table 1. Ethical approval was obtained from the Research Ethics Committee of the Faculty of Physical Therapy, Cairo University. Prior to enrollment, all participants provided written informed consent after receiving a comprehensive explanation of the study objectives, procedures, and their rights as research subjects. All procedures were performed in accordance with the Helsinki Declaration. All participants provided informed written consent prior to participation, aligning with ethical standards for research with human subjects.

Description

Inclusion Criteria:

• he absence of any current or prior musculoskeletal injury or pain affecting the trunk, pelvis, or lower extremities within the preceding six months.

  • absence of neurological, cardiovascular, or systemic conditions that could influence muscle strength or motor performance.
  • a normal BMI relative to their age and sex and were recreationally active without engaging in any structured strength training program targeting the trunk or hip muscles during the three months preceding the study.
  • all participants were able to comprehend the study procedures and provide written informed consent.

Exclusion Criteria:

• any history of musculoskeletal injury, surgery, or chronic pain involving the spine, pelvis, hip, knee, or ankle. Individuals with diagnosed neurological disorders, balance impairments, or vestibular conditions were also ineligible.
• cardiovascular, respiratory, or systemic diseases that could affect physical performance or muscle strength were excluded
• a prior history of lower limb or trunk fractures. Individuals engaged in competitive sports or structured resistance training programs targeting the trunk and lower limb muscles within the preceding three months were not included.
• musculoskeletal deformities, leg length discrepancies, or any other condition that could interfere with the testing procedures

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
trunk muscle peak torque	Isokinetic trunk muscle strength testing	two weeks
hip muscle peak torque	Isokinetic hip muscle strength testing	two weeks

Collaborators and Investigators

• Sponsor: Cairo University
• Investigators: Principal Investigator: Azza M, professor, Cairo University

Publications and helpful links

Helpful Links

• An Optimization Method for Predicting Torque Control of Permanent Magnet Synchronous Motor Models Using Normalized Substitution of Weight Factors

Study record dates

Study Major Dates

• Study Start (Estimated): March 30, 2026
• Primary Completion (Estimated): April 28, 2026
• Study Completion (Estimated): April 30, 2026

Study Registration Dates

• First Submitted: March 27, 2026
• First Submitted That Met QC Criteria: March 27, 2026
• First Posted (Actual): April 2, 2026

Study Record Updates

• Last Update Posted (Actual): April 9, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Body weight; Body mass index; Isokinetic strength; Normalization; Peak torque
• Additional Relevant MeSH Terms: Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Body Weight
• Other Study ID Numbers: Approved by IRB

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No