Groin pain is a common injury in sports such as soccer, ice hockey, tennis and rugby, affecting 4-19% in male and 2-14% in female, which causes time loss from sport career [1, 2]. Adductor related or adductor tendinopathy is less common in comparison with Achilles and hamstrings tendinopathy but takes longer to return to play . It is challenging for practitioners to have a correct diagnosis. In fact, 9 different terms were used based on subjective history, X-ray and MRI images .
· Eccentric hip adductor muscle weakness
· Sudden sideways movements such as dodging, pivoting, changing directions and splitting legs apart to stop a ball)
· Hip abductor and hip adductor weakness supported by [5, 6], but not supported by [7,8].
Signs and symptoms
· 5 seconds squeeze test with NRS (Numeric Rating Scale) higher than 3-10/10 
· Groin pain 
· Increase in muscle soreness and fatigue levels 
Differential diagnosis *
*Terms on the right (figure 1) are not recommended to use as it is lack of specificity and uncertain about the underlying pathology .
*Doha agreement was published in 2015 and new research in 2021 followed up to see how this classification system has been used and prevailed. Although more than 50% of clinicians utilise this classification, some use different system, or do not use any classification and others think this system needs to be more specific .
HAGOS (Copenhagen Hip and Groin Outcome Score)
HOS (Hip Outcomes Score)
IHOT-12 (International Hip Outcome Tool-12)
Hip adductor strengthening exercise
1, Copenhagen adduction exercise (1 easy – 3 hard)
*Upper leg is the one getting strengthened not lower leg in 2 and 3
6-8 weeks of pre-season Copenhagen adduction exercise plus 1 set of 12-15 repetitions of this exercise during season (28 weeks) can prevent groin pain (table 1-5) .
2, Hip sliding
Copenhagen adduction exercise and hip sliding both showed improvements in eccentric hip adduction strength (EHAD), eccentric hip abduction strength (EHAB) and EHAD/EHAB ration . 2-4sets of 6-10reps twice a week over 8weeks.
3, Thera-band hip adduction
This is an option to strengthen hip adduction. Thera-band (elastic band) may not have same outcomes as exercises above since stress on muscle is not even (the highest stimulation is when it is stretched the most) .
The more we exercise, the stronger we get!
Figure 4, the graph of Copenhagen adduction exercise and eccentric hip adduction strength gains 
Sets, repetitions and time under tension
1, Dawkins et al. (2021) investigated the efficacy of low-dose Copenhagen adductor on male foot ball club. In this study, intervention group (IG) was added adductor exercise to normal training. IG performed 2 sets of 5 repetition for first 2 weeks, then increased to 8 repetitions, 10 repetitions, 12 and 15 weekly, which showed no difference between two groups. Although peak hip adductor force increased in the intervention group, strength was not improved [Table 1, 12].
|Week||Sessions||Set per side||Repetitions (Weekly total)|
|week 1-2||2||1||5 (10)|
|Week 3||2||1||5 (10)|
|Week 4||2||1||8 (16)|
|Week 5||2||1||10 (20)|
|Week 6||2||1||15 (30)|
2, In this RCTs, one group performed FIFA 11+ including hamstrings Nordic curl, the other did FIFA 11+ replaced Nordic curl with Copenhagen adduction exercise. The latter improved eccentric hip adduction strength at 8 weeks mark [Table 2, 13].
|Level||Sessions||Set per side||Repetitions (Weekly total)|
3, 8 weeks of progressive Copenhagen adduction exercise increased eccentric hip adduction strength. The first five weeks of exercise was done with isometric hold for 20 seconds, then from week 6, concentric and eccentric contraction were introduced to exercise program [Table 3, 14].
|Week||Sessions||Sets per side||Repetitions (weekly total)||Time under tension per repetition (s)||Total time under tension (s)|
|6||2||3||6 (36)||3s up, 3s down||108|
|7||2||3||8 (48)||3s up, 3s down||144|
|8||2||3||10 (60)||3s up, 3s down||188|
4, Progressive Copenhagen adduction exercise increased eccentric hip adductor strength by 35.7% over 8 weeks [Table 4, 9].
|Week||Sessions/ week||Sets per side||Repetition per side||Total week volume|
|1||2||2||6 (3s up and 3s down)||24|
|2||2||2||8 (3s up and 3s down)||32|
|3||2||2||10 (3s up and 3s down)||40|
|4||2||3||10 (3s up and 3s down)||60|
|5,6||2||3||12 (3s up and 3s down)||72|
|7,8||2||3||15 (3s up and 3s down)||90|
5, Kohavi et al. (2018) examined the efficacy of Copenhagen adductor exercise (CA) and the sliding hip (SH) on football players for eccentric adductor and abductor strength. 8 weeks of progressive exercises increased eccentric abduction and adduction strength by approximately 45% [Table 5, 10].
|Week||Exercise||Sessions per week||Sets per side||Repetitions per side||Weekly volume|
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 Krommes, K., Bandholm, T., Jakobsen, M. D., Andersen, L. L., Serner, A., Holmich, P., & Thorborg, K. (2017). DYNAMIC HIP ADDUCTION, ABDUCTION AND ABDOMINAL EXERCISES FROM THE HOLMICH GROIN-INJURY PREVENTION PROGRAM ARE INTENSE ENOUGH TO BE CONSIDERED STRENGTHENING EXERCISES – A CROSS-SECTIONAL STUDY. International Journal of Sports and Physical Therapy, 12(3), 371–380. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5455186/
 Moreno-Pérez, V., Travassos, B., Calado, A., Gonzalo-Skok, O., Del Coso, J., & Mendez-Villanueva, A. (2019). Adductor squeeze test and groin injuries in elite football players: A prospective study. Physical Therapy in Sport, 37, 54–59. https://doi.org/10.1016/j.ptsp.2019.03.001
 Wörner, T., Thorborg, K., & Eek, F. (2019). Five-Second Squeeze Testing in 333 Professional and Semiprofessional Male Ice Hockey Players: How Are Hip and Groin Symptoms, Strength, and Sporting Function Related? Orthopaedic Journal of Sports Medicine, 7(2), 232596711982585. https://doi.org/10.1177/2325967119825858
 Ishøi, L., Sørensen, C. N., Kaae, N. M., Jørgensen, L. B., Hölmich, P., & Serner, A. (2015). Large eccentric strength increase using the Copenhagen Adduction exercise in football: A randomized controlled trial. Scandinavian Journal of Medicine & Science in Sports, 26(11), 1334–1342. https://doi.org/10.1111/sms.12585
 Kohavi, B., Beato, M., Laver, L., Freitas, T. T., Chung, L. H., & Dello Iacono, A. (2018). Effectiveness of Field-Based Resistance Training Protocols on Hip Muscle Strength Among Young Elite Football Players. Clinical Journal of Sport Medicine, Publish Ahead of Print, 470. https://doi.org/10.1097/jsm.0000000000000649
 Ishøi, L., & Thorborg, K. (2021). Copenhagen adduction exercise can increase eccentric strength and mitigate the risk of groin problems: but how much is enough! British Journal of Sports Medicine, bjsports-2020. https://doi.org/10.1136/bjsports-2020-103564
 Dawkins, J., Ishøi, L., Willott, J. O., Andersen, L. L., & Thorborg, K. (2021). Effects of a low‐dose Copenhagen adduction exercise intervention on adduction strength in sub‐elite male footballers: A randomised controlled trial. Translational Sports Medicine, 1–11. https://doi.org/10.1002/tsm2.238
 Harøy, J., Thorborg, K., Serner, A., Bjørkheim, A., Rolstad, L. E., Hölmich, P., Bahr, R., & Andersen, T. E. (2017). Including the Copenhagen Adduction Exercise in the FIFA 11+ Provides Missing Eccentric Hip Adduction Strength Effect in Male Soccer Players: A Randomized Controlled Trial. The American Journal of Sports Medicine, 45(13), 3052–3059. https://doi.org/10.1177/0363546517720194
 Polglass, G., Burrows, A., & Willett, M. (2019). Impact of a modified progressive Copenhagen adduction exercise programme on hip adduction strength and postexercise muscle soreness in professional footballers. BMJ Open Sport & Exercise Medicine, 5(1), e000570. https://doi.org/10.1136/bmjsem-2019-000570
 Heijboer, W. M., Weir, A., Delahunt, E., Hölmich, P., Schache, A. G., Tol, J. L., de Vos, R. J., Vuckovic, Z., & Serner, A. (2021). A Delphi survey and international e-survey evaluating the Doha agreement meeting classification system in groin pain: Where are we 5 years later? Journal of Science and Medicine in Sport. Published. https://doi.org/10.1016/j.jsams.2021.06.014