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Int J Sports Med
DOI: 10.1055/a-2558-7622
Training & Testing

Comparing unilateral and bilateral assessments of adductor isometric strength symmetries

Tinkara Dolanc
1   Department of Kinesiology, University of Ljubljana Faculty of Sport, Ljubljana, Slovenia (Ringgold ID: RIN162183)
,
Tomaž Hudales
1   Department of Kinesiology, University of Ljubljana Faculty of Sport, Ljubljana, Slovenia (Ringgold ID: RIN162183)
,
Darjan Spudić 
1   Department of Kinesiology, University of Ljubljana Faculty of Sport, Ljubljana, Slovenia (Ringgold ID: RIN162183)
› Author AffiliationsSupported by: Javna Agencija za Raziskovalno Dejavnost RS P5-0147

Registration number (trial ID): The study was approved by the University of Ljubljana, Faculty of Sport Ethics Committee (code: 033-6/2024-41) and adhered to the principles of the Oviedo Convention and the Declaration of Helsinki., Trial registry:, Type of Study: cross-sectional study
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Abstract

This study aimed to evaluate the relationship between unilateral and bilateral assessments of adductor strength, as well as inter-leg adductor strength symmetry, and to assess the intra-session reliability of the results for each testing condition. Nineteen physical education students performed three adductor strength test protocols in a supine position with hips and knees extended: (a) unilateral, (b) bilateral, and (c) bilateral following a unilateral adduction fatigue protocol. Bilateral and unilateral strength measures indicated good–excellent reliability across tests (intraclass correlation coefficient>0.88 and coefficient of variation<8%), while unilateral symmetry showed poor reliability (intraclass correlation coefficient=0.47 and coefficient of variation=13%). Bilateral testing produced statistically significantly higher strength values (p<0.05) than unilateral testing; however, no significant differences were observed between unilateral and bilateral tests under fatigued conditions, regardless of leg preference (preferred or non-preferred). Despite an average strength decrease of 35% after the unilateral fatiguing protocol, bilateral test symmetry results did not change (101% vs. 106%). A very strong correlation was observed between bilateral and unilateral adductor strength results (r=0.81–0.86); yet, no correlation was significant for symmetry results (r<0.35, p>0.05). Due to the limited sensitivity of the bilateral adduction test for detecting changes in symmetry values, we recommend the unilateral testing protocol for practical use when assessing inter-leg adductor muscle strength asymmetries.

Keywords

strength training - validity - prevention - adductor squeeze - groin


Publication History

Received: 04 December 2024

Accepted after revision: 13 March 2025

Accepted Manuscript online:
13 March 2025

Article published online:
01 April 2025

© 2025. Thieme. All rights reserved.

Georg Thieme Verlag KG
Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

 

  • References

  • 1 Wollin M, Thorborg K, Welvaert M. et al. In-season monitoring of hip and groin strength, health and function in elite youth soccer: Implementing an early detection and management strategy over two consecutive seasons. J Sci Med Sport 2018; 21: 988-993
    Search in Google Scholar
  • 2 Harøy J, Clarsen B, Wiger EG. et al. The Adductor Strengthening Programme prevents groin problems among male football players: A cluster-randomised controlled trial. Br J Sports Med 2019; 53: 150-157
    Search in Google Scholar
  • 3 Kekelekis A, Musa RM, Nikolaidis PT, Clemente FM, Kellis E. Hip Muscle Strength Ratios Predicting Groin Injury in Male Soccer Players Using Machine Learning and Multivariate Analysis—A Prospective Cohort Study. Muscles 2024; 3: 297-309
    Search in Google Scholar
  • 4 Bourne MN, Williams M, Jackson J, Williams KL, Timmins RG, Pizzari T. Preseason Hip/Groin Strength and HAGOS Scores Are Associated With Subsequent Injury in Professional Male Soccer Players. J Orthop Sport Phys Ther 2020; 50: 234-242
    Search in Google Scholar
  • 5 Cepedal MQ, Rodríguez GV, Crespo I. et al. Is hip adductor or abductor strength in healthy athletes associated with future groin pain? A systematic review and meta-analysis. Br J Sport Med 2025; 59: 501-509
    Search in Google Scholar
  • 6 Markovic G, Šarabon N, Pausic J, Hadžić V. Adductor Muscles Strength and Strength Asymmetry as Risk Factors for Groin Injuries among Professional Soccer Players : A Prospective Study. Environ Res Public Heal 2020; 17: 1-9
    Search in Google Scholar
  • 7 Yévenes Ulloa A, Altamirano Miranda E, Pereira Parra CP. et al. Relationship between hip muscle strength and lower extremity injuries in soccer players: Systematic review. Sci J Sport Perform 2022; 1: 62-70
    Search in Google Scholar
  • 8 Thorborg K, Bandholm T, Schick M, Jensen J, Hölmich P. Hip strength assessment using handheld dynamometry is subject to intertester bias when testers are of different sex and strength. Scand J Med Sci Sport 2013; 23: 487-493
    Search in Google Scholar
  • 9 Marušič J, Marković G, Šarabon N. Reliability of a New Portable Dynamometer for Assessing Hip and Lower Limb Strength. App Sci 2021; 11: 3391
    Search in Google Scholar
  • 10 Spudić D, Janez V, Vedran H. Validity and Reliability of Hip Strength Assessment using a Frame-stabilized Dynamometer System Device. Meas Phys Educ Exerc Sci 2023; 27: 269-282
    Search in Google Scholar
  • 11 Thorborg K, Branci S, Nielsen MP, Tang L, Nielsen MB, Hölmich P. Eccentric and Isometric Hip Adduction Strength in Male Soccer Players With and Without Adductor-Related Groin Pain. Orthop J Sport Med 2014; 2: 1-6
    Search in Google Scholar
  • 12 Castro MP, Ruschel C, Santos GM, Ferreira T, Pierri C, Roesler H. Isokinetic hip muscle strength: a systematic review of normative data. Sport Biomech 2020; 19: 26-54
    Search in Google Scholar
  • 13 Kozinc Ž, Smajla D, Trajković N, Šarabon N. Reliability of EasyForce Dynamometer for Assessment of Maximal Knee and Hip Strength, and Comparison to Rigid Isometric Dynamometers with External Fixation. Meas Phys Educ Exerc Sci 2022; 26: 232-244
    Search in Google Scholar
  • 14 Martins J, Da Silva JR, Da Silva MRB, Bevilaqua-Grossi D. Reliability and validity of the belt-stabilized handheld dynamometer in hip-and knee-strength tests. J Athl Train 2017; 52: 809-819
    Search in Google Scholar
  • 15 Desmyttere G, Gaudet S, Begon M. Test-retest reliability of a hip strength assessment system in varsity soccer players. Phys Ther Sport 2019; 37: 138-143
    Search in Google Scholar
  • 16 Nielsen MF, Thorborg K, Krommes K. et al. Hip adduction strength and provoked groin pain: A comparison of long-lever squeeze testing using the ForceFrame and the Copenhagen 5-Second-Squeeze test. Phys Ther Sport 2022; 55: 28-36
    Search in Google Scholar
  • 17 Marušič J, Šarabon N. Hip adduction and abduction strength in youth male soccer and basketball players with and without groin pain in the past year. PLoS One 2022; 17: e0275650
    Search in Google Scholar
  • 18 Ribič A, Hadzic V, Spudić D. et al. Hip adduction and abduction strength in different test positions and their relationship to previous groin injuries in women footballers. Res Sport Med 2024; 32: 1055-1066
    Search in Google Scholar
  • 19 Blättler M, Bizzini M, Schaub G. et al. Assessment of hip abductor and adductor muscle strength with fixed-frame dynamometry: Considerations on the use of bilateral and unilateral tasks. Phys Ther Sport 2024; 70: 22-28
    Search in Google Scholar
  • 20 Lovell GA, Blanch PD, Barnes CJ. EMG of the hip adductor muscles in six clinical examination tests. Phys Ther Sport 2012; 13: 134-140
    Search in Google Scholar
  • 21 Breen D, Farrell G, Delahunt E. The clinical assessment of hip muscle strength in professional rugby union players. Phys Ther Sport 2021; 52: 115-120
    Search in Google Scholar
  • 22 Dunne C, Callaway AJ, Thurston J, Williams JM. 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; 57: 46-52
    Search in Google Scholar
  • 23 Howard JD, Enoka RM. Maximum bilateral contractions are modified by neurally mediated interlimb effects. J Appl Physiol 1991; 70: 306-316
    Search in Google Scholar
  • 24 Škarabot J, Cronin N, Strojnik V, Avela J. Bilateral deficit in maximal force production. Eur J Appl Physiol 2016; 116: 2057-2084
    Search in Google Scholar
  • 25 Ebben WP, Flanagan E, Jensen RL. Bilateral Facilitation and Laterality during the Countermovement Jump. Percept Mot Skills 2009; 108: 251-258
    Search in Google Scholar
  • 26 Thorborg K, Serner A, Petersen J, Madsen TM, Magnusson P, Hölmich P. Hip adduction and abduction strength profiles in elite soccer players: Implications for clinical evaluation of hip adductor muscle recovery after injury. Am J Sports Med 2011; 39: 121-126
    Search in Google Scholar
  • 27 Bishop C, Read P, Chavda S, Turner A. Asymmetries of the Lower Limb: The Calculation Conundrum in Strength Training and Conditioning. Strength Cond J 2016; 38: 27-32
    Search in Google Scholar
  • 28 Hopkins WG. Measures of Reliability in Sports Medicine and Science. Sport Med 2000; 30: 1-15
    Search in Google Scholar
  • 29 Cormack SJ, Newton RU, Mcguigan MR, Doyle TL. Reliability of measures obtained during single and repeated countermovement jumps. Int J Sports Physiol Perform 2008; 3: 131-144
    Search in Google Scholar
  • 30 Koo TK, Li MY. A Guideline of Selecting and Reporting Intraclass Correlation Coefficients for Reliability Research. J Chiropr Med 2016; 15: 155-163
    Search in Google Scholar
  • 31 Kotrlik JW, Williams HA. The Incorporation of Effect Size. Inf Technol Learn Perform J 2003; 21: 1-7
    Search in Google Scholar
  • 32 Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986; 1: 307-310
    Search in Google Scholar
  • 33 Cohen J. Statistical Power Analysis for the Behavioral Sciences. 2nd edn New Jersey: Lawrence Erlbaum; 1988
    Search in Google Scholar
  • 34 Tyler TF, Nicholas SJ, Campbell RJ, McHugh MP. The association of hip strength and flexibility with the incidence of adductor muscle strains in professional ice hockey players. Am J Sports Med 2001; 29: 124-128
    Search in Google Scholar
  • 35 Whittaker JL, Small C, Maffey L, Emery CA. Risk factors for groin injury in sport: An updated systematic review. Br J Sports Med 2015; 49: 803-809
    Search in Google Scholar
  • 36 Janzen CL, Chilibeck PD, Davison KS. The effect of unilateral and bilateral strength training on the bilateral deficit and lean tissue mass in post-menopausal women. Eur J Appl Physiol 2006; 97: 253-260
    Search in Google Scholar
  • 37 Secher NH, Rube N, Elers J. Strength of two- and one- leg extension in man. Acta Physiol Scand 1988; 134: 333-339
    Search in Google Scholar
  • 38 Jakobi JM, Chilibeck PD. Bilateral and unilateral contractions: possible differences in maximal voluntary force. Can J Appl Physiol 2001; 26: 12-33
    Search in Google Scholar
  • 39 Ye X, Miller WM, Jeon S, Carr JC. Sex comparisons of the bilateral deficit in proximal and distal upper body limb muscles. Hum Mov Sci 2019; 64: 329-337
    Search in Google Scholar
  • 40 Anders JPV, Keller JL, Smith CM. et al. Performance fatigability and the bilateral deficit during maximal, isokinetic leg extensions in men and women. 2021; 29: 59-66
    Search in Google Scholar
  • 41 Tourville TW, Smith HC, Shultz SJ. et al. Reliability of a New Stabilized Dynamometer System for the Evaluation of Hip Strength. Sports Health 2013; 5: 129-136
    Search in Google Scholar