Husain MA1,2, Griffiths C2, Schilders E2,3,4,5, Cooke CB6
1University of Bahrain, College of Health Sciences, Sakheer, Bahrain, 2Leeds Beckett University, Institute for Sport Physical Activity & Leisure, Leeds, United Kingdom, 3Fortius Clinic, London, United Kingdom, 4Wellington Hospital, London, United Kingdom, 5Yorkshire Clinic, Bradford, United Kingdom, 6Leeds Trinity University, School of Social and Health Sciences, Leeds, United Kingdom
Background: The use of hand-held dynamometers (HHD) stabilization platforms can reduce the measurement error associated with the manual application of HHD in testing hip muscle strength, which is supported by previous research. The Hip Strength Assessment Platform [STAPH] was introduced as an improved version of a previous testing platform (The Groin Abductor-Adductor Strength Platform [GrAASP]).
Purpose: This study investigated the validity and reliability of STAPH. Hip abductor (ABD), adductor (ADD), flexor (FLEX), extensor (EXT), internal (IR) and external rotator (ER) together with knee flexion (KFL) muscle strength was measured using STAPH in two consecutive sessions.
Methods: Twenty-one injury-free and active participants (mean age: 19.68±1.63 years; mean BMI: 23.51±3.36 kg.m-²) were assessed for bilateral hip ABD, ADD, FLEX, EXT, IR, ER, and KFL maximal isometric strength using a HHD (MicroFET2, Hoggan Health Industries, UT, USA). The MicoFET2 was stabilized on the STAPH using a specific support system. The participants were positioned in supine, side-lying and seated positions, and the MicroFET2 was placed distally (above the ankle) for testing. All participants were tested in two consecutive sessions within 7 to 10 days. All participants were instructed not to change their exercise or diet regimens. Both hip sides and sexes were compared using repeated measures ANOVA. Limits of agreement (LOA) between the two testing sessions was calculated according to Bland-Altman, mean of difference (MD) and measurement error (ME).
Results: No difference in torque values was found between the dominant and non-dominant sides (p>0.05). HAB and HIR had the least bilateral torque deficits (1.2% and 0.3% respectively), in comparison to HFL (7.1%), which showed the highest torque deficit. Males were stronger than females in all measurements of the dominant side without statistically significant differences (p>0.05). MicroFET2 test-retest had the smallest change in scores in HIR (MD = 0.16 N·m, 95% AL [-14.05, 14.37], ME = ±10.6%, p >0.05) and HAB testing (MD=0.50 N·m, 95% AL [-16.75, 117.75], ME = ±11.7%, p >0.5). HAD testing showed the biggest change in scores (MD = 4.99 N·m, 95% AL [-5.34, 115.32], ME= ±8.74%,p =0.001) between the two sessions. KFL testing showed the highest measurement error (MD = 1.08 N·m, 95% AL [-34.85, 37.01], ME =±14.6%,p >0.05).
Conclusion(s): Healthy, active and injury free individuals show less than 10% bilateral isometric torque deficits. Regarding sex differences, males have higher isometric hip muscle torque values compared to females. Utilizing the STAPH in strength testing showed lower measurement error for the hip muscles compared to the knee flexor muscle.
Implications: STAPH is a valid, reliable and portable tool to test hip muscle strength in both sexes with low measurement error. Also, clinicians are generally encouraged to stabilize the HHD to improve the validity and reliability of measurements.
Keywords: Muscle strength testing, Hip Joint
Funding acknowledgements: This project was funded by Leeds Beckett University.
Purpose: This study investigated the validity and reliability of STAPH. Hip abductor (ABD), adductor (ADD), flexor (FLEX), extensor (EXT), internal (IR) and external rotator (ER) together with knee flexion (KFL) muscle strength was measured using STAPH in two consecutive sessions.
Methods: Twenty-one injury-free and active participants (mean age: 19.68±1.63 years; mean BMI: 23.51±3.36 kg.m-²) were assessed for bilateral hip ABD, ADD, FLEX, EXT, IR, ER, and KFL maximal isometric strength using a HHD (MicroFET2, Hoggan Health Industries, UT, USA). The MicoFET2 was stabilized on the STAPH using a specific support system. The participants were positioned in supine, side-lying and seated positions, and the MicroFET2 was placed distally (above the ankle) for testing. All participants were tested in two consecutive sessions within 7 to 10 days. All participants were instructed not to change their exercise or diet regimens. Both hip sides and sexes were compared using repeated measures ANOVA. Limits of agreement (LOA) between the two testing sessions was calculated according to Bland-Altman, mean of difference (MD) and measurement error (ME).
Results: No difference in torque values was found between the dominant and non-dominant sides (p>0.05). HAB and HIR had the least bilateral torque deficits (1.2% and 0.3% respectively), in comparison to HFL (7.1%), which showed the highest torque deficit. Males were stronger than females in all measurements of the dominant side without statistically significant differences (p>0.05). MicroFET2 test-retest had the smallest change in scores in HIR (MD = 0.16 N·m, 95% AL [-14.05, 14.37], ME = ±10.6%, p >0.05) and HAB testing (MD=0.50 N·m, 95% AL [-16.75, 117.75], ME = ±11.7%, p >0.5). HAD testing showed the biggest change in scores (MD = 4.99 N·m, 95% AL [-5.34, 115.32], ME= ±8.74%,p =0.001) between the two sessions. KFL testing showed the highest measurement error (MD = 1.08 N·m, 95% AL [-34.85, 37.01], ME =±14.6%,p >0.05).
Conclusion(s): Healthy, active and injury free individuals show less than 10% bilateral isometric torque deficits. Regarding sex differences, males have higher isometric hip muscle torque values compared to females. Utilizing the STAPH in strength testing showed lower measurement error for the hip muscles compared to the knee flexor muscle.
Implications: STAPH is a valid, reliable and portable tool to test hip muscle strength in both sexes with low measurement error. Also, clinicians are generally encouraged to stabilize the HHD to improve the validity and reliability of measurements.
Keywords: Muscle strength testing, Hip Joint
Funding acknowledgements: This project was funded by Leeds Beckett University.
Topic: Musculoskeletal: lower limb; Outcome measurement; Sport & sports injuries
Ethics approval required: Yes
Institution: Leeds Beckett University
Ethics committee: Local Research Ethics Coordinator
Ethics number: NA
All authors, affiliations and abstracts have been published as submitted.
