Validity, reliability, minimal detectable change, and methodological considerations for HHD and portable fixed frame isometric hip and groin strength testing: A comparison of unilateral and bilateral testing methods

Cian Dunne; Andrew J Callaway; Joanna Thurston; Jonathan M Williams

doi:10.1016/j.ptsp.2022.07.002

Validity, reliability, minimal detectable change, and methodological considerations for HHD and portable fixed frame isometric hip and groin strength testing: A comparison of unilateral and bilateral testing methods

Phys Ther Sport. 2022 Sep:57:46-52. doi: 10.1016/j.ptsp.2022.07.002. Epub 2022 Jul 8.

Authors

Cian Dunne¹, Andrew J Callaway², Joanna Thurston¹, Jonathan M Williams¹

Affiliations

¹ Department of Rehabilitation and Sport Sciences, Bournemouth University, BH12 5BB, UK.
² Department of Rehabilitation and Sport Sciences, Bournemouth University, BH12 5BB, UK. Electronic address: acallaway@bournemouth.ac.uk.

PMID: 35921781
DOI: 10.1016/j.ptsp.2022.07.002

Abstract

Objectives: Comparative assessment of bilateral (KangaTech) and unilateral (HHD) testing modalities through concurrent validity and test-retest reliability. Methodological considerations explored include minimum repetitions and comparison of average and maximum values.

Design: Experimental, observational.

Setting: Biomechanics laboratory.

Participants: Thirty-three participants.

Main outcome measures: Concurrent validity using peak force. Test-retest reliability used Abduction and Adduction using 2 trials, randomised between devices. Maximum peak force and average of both trials were used.

Results: HHD and KT360 are concurrently valid (r = 0.996); with no significant difference (z = -0.681). Excellent HHD reliability (ICC:0.92-0.96) and KT360 (ICC:0.89-0.97). Significant difference between max peak force and average peak force but within the calculated MDC(%). No significant differences between max peak force between trials. Spearman-Brown prophecy predicted excellent reliability for one trial (ICC:0.81-0.95). Bilateral facilitation was demonstrated using the KT360 with 94.6-101.2% increase in force compared to HHD.

Conclusions: With no significant difference between first and second max effort, and excellent prophesised reliability, one rep max effort should be acceptable to use. Body positioning within the KT360 seems to elicit bilateral facilitation rather than deficit, therefore unilateral and bilateral force values are not interchangeable.

Keywords: Bilateral testing; Groinbar; Handheld dynamometer; Isometric; Kangatech; Unilateral testing.