Related Experiment Video
Updated: May 9, 2026
Lower Limb Biomechanical Analysis of Healthy Participants
Published on: April 15, 2020
The validity and reliability of a customized rigid supportive harness during Smith machine back squat exercise
Brendan R Scott1, Ben J Dascombe, Jace A Delaney
11Applied Sport Science and Exercise Testing Laboratory, Faculty of Science and Information Technology, University of Newcastle, Ourimbah, Australia; 2Priority Research Center in Physical Activity and Nutrition, University of Newcastle, Callaghan, Australia; 3Biomedical Sciences and Pharmacy, Faculty of Health, University of Newcastle, Ourimbah, Australia; and 4New South Wales Institute of Sport, Sydney Olympic Park, Sydney, Australia.
A new harness back squat (HBS) effectively measures one-repetition maximum (1RM) in resistance-trained men. This exercise variation is a valid and reliable alternative for individuals with limited shoulder mobility.
Area of Science:
- Sports Science
- Biomechanics
- Exercise Physiology
Background:
- The traditional back squat is a foundational exercise for athletic and clinical populations.
- Restricted glenohumeral mobility can prevent safe execution of the back squat, limiting assessment of maximal strength.
- Alternative methods are needed to accurately quantify strength in individuals with shoulder limitations.
Purpose of the Study:
- To determine the validity and reliability of a novel harness back squat (HBS) for assessing one-repetition maximum (1RM).
- To evaluate the HBS as a tool for individuals with restricted glenohumeral mobility.
Main Methods:
- Thirteen resistance-trained young men participated in three lab sessions separated by one week.
- One-repetition maximum (1RM) was assessed using the traditional back squat (session 1) and the harness back squat (HBS; sessions 2 and 3).
- Validity was assessed by correlating traditional back squat 1RM with HBS 1RM; reliability was assessed using intraclass correlation coefficient (ICC) and coefficient of variation (CV).
Main Results:
- Mean 1RM values were 148.4 ± 25.0 kg (traditional back squat), 152.5 ± 25.7 kg (HBS1), and 150.4 ± 22.6 kg (HBS2).
- A very strong correlation (r = 0.96) was found between traditional back squat and HBS 1RM scores.
- The HBS demonstrated high test-retest reliability (ICC = 0.98, CV = 2.6%).
Conclusions:
- The harness back squat (HBS) is a valid and reliable method for assessing 1RM in young men with resistance training experience.
- The HBS offers a practical solution for strength assessment in individuals with restricted glenohumeral mobility.
