Groin Strain

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Original Editors - Els Van Haver

Top Contributors - Vidya Acharya, Astrid Lahousse, Geubels Kaat, Nele Kiekens, Mats Vandervelde, Prince Wilson, Kim Jackson, Admin, Laure Lievens, Wanda van Niekerk, Lucinda hampton, Kai A. Sigel, Joao Costa, Uchechukwu Chukwuemeka, 127.0.0.1, Leana Louw, George Prudden, Claire Knott, Rachael Lowe, Els Van Haver and Naomi O'Reilly  

Search Strategy

Keywords:

Groin tendinitis, adductor strain, adductor tendinitis, iliopsoas strain, iliopsoas tendinitis, abdominal strain, abdominal tendinitis, muscle strains, groin pain

Databases searched:
Pedro, google scholar, Pubmed, Web of Knowledge and Library of the VUB

Definition/Description

A groin strain is an injury to the muscle tendon unit that produces pain on palpation of the adductor tendons or its insertion on the pubic bone with or without pain during resisted adduction.(1) 
Groin muscle strains are encountered more frequently in ice hockey and soccer than other sports.
These sports require a strong eccentric contraction of the adductor musculature during competition and practice. (2)
The underlying injury is most often a muscle or tendon strain at the insertion of the tendon of the adductor muscle to the bone. (3) 

The difference between groin tendinopathy and strain are:
- First of all strains are acute and tendinosis are chronic. A tendinosis is a repetitive strain.
- The second difference is that acute injuries are more often localized in the myotendon junctions and chronic injuries are localized at the tendinous insertions on the pubic bone.
Fig. 2 (3) Evidence Based Practice: 5
+ Link Physiopedia: http://www.physio-pedia.com/Muscle_Strain
+ Link Physiopedia: http://www.physio-pedia.com/Adductor_Tendinitis

Clinically Relevant Anatomy

In human anatomy, the groin is the junctional area between the abdomen and the thigh on either side of the pubic bone. This is also known as the medial compartment of the thigh.
The groin muscles consist of three large groups of muscles that can be injured:
The abdominal-, iliopsoas- and adductors-group.

1. The adductors group:
The adductors of the hip joint include 6 muscles: the adductor longus, magnus, and brevis and the gracilis, obturator externus, and pectineus. All these are innervated by the obturator nerve, with the exception of the pectineus, which receives innervation from the femoral nerve. The primary function of this muscle group is adduction of the thigh in open chain motions and stabilization of the lower extremity and pelvis in closed chain motion. The adductor longus is most commonly injured during sporting activity. (4) 
The proximal attachment of the adductor longus contributes to an anatomical pathway across the anterior pubic symphysis that is likely required to withstand the transmission of large forces during multidirectional athletic activities. Its lack of mechanical advantage may make it more susceptible to strain.(21) 

As shown in fig 1., the adductors all originate on the pubic ramus as almost all insert on the linea aspera of the posterior femur. The posterior head of the adductor magnus has a proximal attachement on the ischial tuberosity antero-inferoirly and attaches distally on the medial distal femur at the adductor tubercle. The gracilis insertion is on the medial border of the tuberosity of the tibia. (3) 
+ Link physiopedia: http://www.physio-pedia.com/Hip_Anatomy

2. The abdominal group:
The abdominal musculature comprise the rectus abdominis, the obliques internus and externus abdominis.
+ link naar Physiopedia: http://www.physio-pedia.com/Abdominal_Muscle_Anatomy

3. The iliopsoas group:
The iliopsoas, comprised of iliacus and psoas major muscles, is the only muscle directly connecting the spine and the lower limb. (2)
+ Link physiopedia: http://www.physio-pedia.com/Hip_Anatomy

 

Epidemiology /Etiology

Groin strains are common amongst athletes who compete in sports that involve repetitive twisting, turning, sprinting and kicking. (5) Evidence Based Practice: 3B
Strain injuries to the groin are among the most common groin injuries in adult male soccer players. Groin strain accounts for 11% to 16% of all soccer injuries. (6) Evidence Based Practice: 2B
Groin strains are also known from other sports such as ice hockey, running, tennis, rugby, American football, basketball and others. (7) Evidence Based Practice: 1B

The exact incidence of groin muscle strains in most sports is unknown because athletes often play through minor groin pain and the injury goes unreported. In addition, overlapping diagnoses can skew the incidence. (4) Evidence Based Practice: 1A

Musculotendinous injuries to the groin are mainly a consequence of cumulative microtraumas (overuse trauma, repeated minor injuries) leading to chronic groin pain. Cumulative or single injury seem to be important etiological factors. Although in some cases groin pain is due to an acute injury, typically a direct injury to the soft tissues resulting in muscle haematoma, the underlying injury is most often a muscle or tendon strain at the tendinous insertion of the adductor muscles to the bone. A chronic tendinitis of the adductor muscles/tendons, especially that of the adductor longus, is the most frequently diagnosed (9) Evidence Based Practice: 5

Injury mechanism can be divided in 3 groups:
1. Direct blunt trauma
2. Forceful contraction
3. Microtrauma by repetitive injury
And subsequently result in muscle contusions, avulsions, tears and strains. (8) Evidence Based Practice: 2A
Most common groin injury in athletes are muscle and tendon strain of the adductor muscle group. A common mechanism of this injury is when the adductors attempt to decelerate an extending, abducting leg by using an eccentric contraction to adduct and flex the hip. With the forceful eccentric contraction, the adductors may not be strong enough to withstand the force, and injury can occur. The injury may also occur during a forceful concentric contraction of the muscle.(8) Evidence Based Practice: 2A

Lower-extremity athletes such as ice hockey and soccer players are naturally more prone to this pathology due to the importance of the hip adductors in lower-extremity performance,(11) Evidence Based Practice: 4
who are sports that involve repetitive twisting, turning, sprinting and kicking. (5) Evidence Based Practice: 3B

Characteristics/Clinical Presentation

The main sign of the adductor muscle injury is intense pain in the groin area.
+ Link Physiopedia: http://www.physio-pedia.com/Adductor_Tendinitis

The muscles that cross multiple joints or have a complex structure are more sensitive to strain injury. Strain injuries often arise from excessive stretching or stretching when the muscle is being activated. When there is a strain in the muscle, the damage is often localized near the muscle tendon junction. The muscle is getting weaker and the risk for further injury rises. (13) Evidence Based Practice: 5
+ Link Physiopedia: http://www.physio-pedia.com/Muscle_Strain

Clinically for an adductor strain, the patient presents with pain in the inner thigh and tenderness along the muscle belly, tendon or insertion. The pain is exacerbated by adduction. There is no loss of strength or range of movement. (10) Evidence Based Practice: 5

Tears frequently occur at the myotendinous junction, which is the weakest part of the muscle tendon unit, but is also commonly seen in the muscle belly. The same mechanism of injury that results in a muscle tear in an adult may cause an apophyseal avulsion in an adolescent. There is a well-established clinical grading system for muscle tears, which has 3 components:
- Grade 1: no loss of function or strength
- Grade 2: severe, with some weakness
- Grade 3: complete muscle tear and complete functional loss (8) Evidence Based Practice: 2A

Grade 1 muscle tears can show normal appearances or a small area of focal disruption (<5% of the muscle volume), with hematoma and perifascial fluid relatively common on imaging with US and MRI.
Grade 2 injury corresponds to a partial tear, with muscle fiber disruption seen (>5% of the muscle volume) but not affecting the whole muscle belly.
Grade 3 injuries are complete muscle tears with frayed margins and bunching and/or retraction of the torn muscle fibers. (8) Evidence Based Practice: 2A

• In acute grade I or II strains of the adductor muscle, there is a very intense pain in the groin area, like a sudden stab with a knife, if the athlete attempts to continue the activity. Locally a hemorrhage and swelling can be seen a few days after the injury. A typical trauma history, localized tenderness and difficulties to contract the hip abductors.

• Complete muscle tears or grade III strains are most often found in the distal musculotendinous junction located toward the insertion on the femur.

• In chronic cases, the symptoms of groin injury are often complex and uncharacteristic. With time, as the injury becomes more chronic, there is a tendency for the pain to radiate out distally along the medial aspect of the thigh or proximally toward the rectus abdominis. In chronic and subchronic cases, the symptoms are often vague and diffuse in location. The most common symptoms are pain during exercise, stiffness after exercise and in the morning, as well as pain at rest.
Stress fractures of femoral neck or the inferior ramus of the pubic bone can be revealed by bone scintigraphy or repeated radiographic examinations. (9) Evidence Based Practice: 5

Differential Diagnosis

The literature provides no consensus on diagnostic criteria for the various causes of groin pain among athletes. (7) There is also no consensus on definitions for groin injuries and the diagnosis is often difficult because of the wide variety of different diseases that can cause pain to the groin area. (6) The insertions of the rectus abdominis and adductor longus muscles are also very close to each other, which may result in difficulties in the differential diagnosis between tendinitis or partial rupture of these muscles. (9) Evidence Based Practice: 5

Diagnostic Procedures

Further investigations such as an MRI scan or Ultrasound may be required. In rare cases to confirm diagnosis and assess the severity of injury.

Patients with chronic pains are more difficult to diagnose. There pain is more diffuse and that is difficult to attribute to specific structures. The presentations for osteitis pubis, sports hernia (<R> http://www.physio-pedia.com/Pubalgia) and chronic adductor pain are quite similar and can present simultaneously. Plain radiographs or a bone scan can sow typical changes of osteitis pubis and herniography can rule out sports hernia. Ultrasound of MRI can evaluate the tendon structure for intrasubstance abnormalities.¹⁴

Outcome Measures

Strength testing ¹⁵

The best way to test strength and inhibition of the adductor muscles is through the ‘Adductor Squeeze’ test ¹⁶. This is done with the patient lying on the table with the legs extended. The examiner places two clenched fists together between the patient’s knees and the patient then squeezes the knees onto the examiner’s fists. With acute injuries, it is advisable that the patient is instructed to slowly build pressure until maximum pressure is achieved. Pain and inhibition are then subjectively assessed. The same test is then done with the feet up on the table and the knees bent to 45 degrees. The third and final position is feet off bench with hips at 90 degrees. It is necessary to test all three positions, as acute tears may actually be pain-free in one of these testing positions.¹⁷ Level of evidence: 3B

The purpose of these tests is to qualify pain and inhibition at all testing positions and to gain some ‘asterix’ points for re-assessment in the near future.

Examination

The patients typically complain about aching groin or medial thigh pain and often relate a specific inciting incident. Sometimes acute rupture and osseous avulsion of the proximal adductor longus can be reported.

The passive examination learns the physiotherapist there is tenderness to palpation with focal swelling along the adductors and decreased adductor strength. While testing the muscle strength the pain will increase with resisted adduction.^14,18,19

Prevention ²⁷

- Keep your adductor muscles strong to absorb the energy of sudden physical stress
- Exercise program
- Learn the proper technique for exercises and sports
- Warm up your muscles slowly and stretch them properly

Medical Management

Most of the times the management is nonoperative. Injection at the adductor longus enthesis is helpful. In cases of acute rupture, open surgical repair with suture anchors has been described with good results.

NSAID’s (non-steroidal anti-inflammatory medications) can be used to control pain and decrease the swelling. Furthermore there is no need of other medication. (<R> http://www.physio-pedia.com/NSAID_Gastropathy)

Physical Therapy Management

The therapy can be divided into 4 stages. ²⁰

The first stage will implicate the RICE principal: Rest, ice, compression and elevation. This stage is designed to limit the swelling and prevent any further injury. Rest until pain free. This way the muscle can heal appropriately. When you rest inadequately it may prolong the recovery. Allow pain to guide your level of activity. Avoid activities that place extra stress on these muscles. Don’t do activities that cause pain (running, jumping and weight lifting using the leg muscles ). If normal walking hurts, shorten your stride. And do not play sports. This stage continues until the pain and swelling decrease (can depends from 2 days till one week). NAIDS can be used to control pain and decrease the swelling. The applying of ice is recommended in the first 48 hours after the injury as well later on after activities. Ice stimulates the blood flow to the injured area and calms the inflammatory response, ^10,16,20,24 hoogste level of evidence 1B.

The second stage is based on limiting atrophy and restore the ROM (Range of Motion). It begins with gentle passive and active assisted motion. The exercises containing to improve the range of motion must be limited by the pain,²¹ level of evidence 1A. Stretching can be helpful as long it is not painful. When you stretch excessively, it can be harmful and it will slow the recovery and healing process. When the acute pain is gone, start gentle stretching as recommended. Stay within pain limits. Hold each stretch for about 10 seconds and repeat 6 times. Stretch several times a day. Sometimes ultrasound (<R> http://www.physio-pedia.com/Ultrasound_therapy) and electrical stimulation (<R> http://www.physio-pedia.com/Transcutaneous_Electrical_Nerve_Stimulation_(TENS)) can be added, although it has not fully scientifically verified.

Stage 3 begins when the patient has a nearly full range of motion pain free. It’s based in regaining strength, flexibility and to improve the endurance. First we train isometric and isokinetic, starting with low weight and 3-4 repetitions. We can progress to heavier weight and fewer repetitions as the pain free strength improves,²² Level of evidence 1B.

The fourth and final stage includes proprioceptive training, sport specific training (very important because most of our patients with groin strains are athletes). Eccentric training is allowed in this stage, because this stage can begin only when the patient is pain free and reached about 70% of his normal strength,²³ level of evidence 1A.

The key component of rehabilitation for groin pain in athletes is the exercise therapy. Exercise, particularly strengthening exercise of the hip and abdominal muscles is important. Recommended to do the exercises in the form of progressive exercises (static to functional) and performed through range,¹⁸ level of evidence 2B.

Stretching exercises can be used in prevention and also as an extra factor after the acute phase and there can be added manual therapy ,²⁴ level of evidence: 1B. 2 examples of stretches are:

Groin squeezes:²⁵

Begin this exercise by lying in the position demonstrated with a rolled towel or ball between your knees. Slowly squeeze the ball between your knees tightening your groin muscles (adductors). Hold for 5 seconds and repeat 10 times as hard as possible pain free.

Groin Stretch:²⁶
Stand tall with your back straight and your feet twice shoulder width apart. Start a lunge to one side, the other knee remains straight, until you feel a stretch in the groin.Hold 5 seconds and repeat 10 times at a mild to moderate stretch provided the exercise is pain free.

Key Research

- Timothy F. Tyler, MS, PT, ATC, et al. Groin Injuries in Sports Medicine. Sports Health May 2010; 2(3): 231-136. Level of Evidence: 2A
- Maffey L, Emery C.; What are the risk factors for groin injury in sport? A systematic review of the literature. Sports Med. 2007, 37(10): 881-94. Level of Evidence: 1A
- Scott A. Lynch, Per A.F.H. Renström; Groin injuries in Sport, Treatment Strategies. Sports Med. 1999 August. 28 (2): 137-144. Level of Evidence: 3A
- Almeida MO, Silva BN, Andriolo RB, Atallah AN, Peccin MS. Conservative interventions for treating exercise-related musculotendinous, ligamentous and osseous groin pain. Chohrane Database Syst Rev. Jun 2013 Level of Evidence: 1A
- Machotka Z, Kumar S, Perraton LG. A Systematic Review of the Literature on the Effectiveness of exercise therapy for groin pain in athletes. Sports Med Arthrosc Rehabil Ther Technol. Mar 2009 1(1): 5. Level of Evidence 1A

Resources

Mount Sinai Hospital: Health Library: Groin Strain. http://www.mountsinai.org/patient-care/health-library/diseases-and-conditions/groin-strain. (accessed on 26 October 2014)

View references

Clinical Bottom Line

A groin strain or a groin pull is an acute tear of the small fibers of the adductor muscles. This tear can be partial or complete. Groin strain is usually due to an acute stretch of the muscle often at the same time of a forceful contraction or repetitive functional overloading. The adductor muscles are a group of muscles that are located on the inner side of the thigh. They start in the groin area and run down the inner thigh to attach to the inner side of the knee. They are particularly active when suddenly changing direction and unexpected movements. The foremost function of the adductor muscles is adduction of the thigh in open chain movements and stabilization of the lower extremity and pelvis in closed chain movements The most common sign of a groin strain is a sudden sharp pain or pulling sensation during activity in the inner thigh. During activities the patient experience an increase in pain. Most of the times the management is non-operative. Injection at the adductor longus enthesis is helpful.

Recent Related Research (from Pubmed)

-http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445110/
-http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2989399/
-http://bjsm.bmj.com/content/14/1/30.long

References

¹Engebretsen AH, Myklebust G, Holme I, Engebretsen L, Bahr R. Intrinsic risk factors for groin injuries among male soccer players: a prospective cohort study. Am J Sports Med. 2010 Oct; 38 (10): 2051-2057. Level of Evidence: 2B
²Groin Anatomy: David Mc Gettigan, Sports Rehabilitation BSC.HONS., Tag: Adductor. http://davidmcgettigan.ie/tag/adductor/ (accessed on 21 November 2014)) Level of Evidence: 5
³Skelett- und Weichteil- Topographie: anatomie und schmerz: Picture 2: Os Coxae lateral and mediaal. http://www.anatomie-und-schmerz.de/Referate/2004/skelett.html (accesed on 18 December 2014)
⁴Timothy F. Tyler, MS, PT, ATC, et al. Groin Injuries in Sports Medicine. Sports Health May 2010; 2(3): 231-136. Level of Evidence: 2A
⁵Arnason A, Sigurdsson SB, Gudmundsson A, et al. Risk factors for injuries in football. Am J Sports Med. 2004;32:5S-16S. Level of Evidence: 2B
⁶Maffey L, Emery C.; What are the risk factors for groin injury in sport? A systematic review of the literature. Sports Med. 2007, 37(10): 881-94. Level of Evidence: 1A
⁷Hagglund M, Walden M, Ekstrand J. Previous injury as a risk factor for injury in elite football: a prospective study over two consecutive seasons. Br J Sports Med. 2006;40:767-772. Level of Evidence: 3B
⁸Maffey L, Emery C. What are the risk factors for groin injury in sport? A systematic review of the literature. Sports Med. 2007; 37(10): 881-94. Level of Evidence: 1A
⁹Emery CA, Meeuwisse WH. Risk factors for groin injuries in hockey. Med Sci Sports Exerc. 2001;33:1423-1433. Level of Evidence: 2B
¹⁰NYU Langone Medical Center: Groin Strain. http://www.med.nyu.edu/content?ChunkIID=11822. (accessed on 27 October 2014) Level of Evidence: 5
¹¹Morelli V, Smith V. Groin injuries in athletes. Am Fam Physician. 2001 Oct; 64(8): 1405-14. Level of Evidence: 1A
¹²Sports Injury Clinic: Groin Strain Assessment. http://www.sportsinjuryclinic.net/sport-injuries/hip-groin-pain/groin-strain/assessment-diagnosis-groin-strain. (Accessed on 20 October 2014) Level of Evidence: 5
¹³McSweeney SE, Naraghi A, Salonen D, Theodoropoulos J, White LM. Hip and Groin Pain in the Professional Athlete. Can Assoc Radiol J. May 2012: 63(2): 87-99 Level of Evidence: 2B
¹⁴Lisa M. Tibor, M.D., Jon K. Sekiya, Differential Diagnosis of Pain Around the Hip Joint. Arthroscopy: The Journal of Arthroscopic & Related Surgery 2008 December, 24(12) 1407-1421. Level of Evidence: 3A
¹⁵Sports Injury Bulletin, Archive: Groin-Injuries. http://www.sportsinjurybulletin.com/archive/groin-injuries.html# (accessed 18 November 2014). Level of Evidence: 5
¹⁶Nevin F, Delahunt E. Adductor squeeze test values and hip joint range of motion in Gealic Football atheletes with longstanding groin pain. J Sci Med Sport. 2014 Mar; 17 (2): 155-9 Level of Evidence: 3B
¹⁷Delahunt E, Kennelly C, McEntee BL, Coughlan GF, Green BS. The thigh adductor squeeze test: 45° flexion as the optimal test postion for eliciting adductor muscle activity and maximum pressure values. Man Ther. 2011 Oct; 16(5): 476-80 Level of Evidence: 3B
¹⁸Martin RL, Sekiya JK. The Interrater Reliability of 4 clinical tests used to assess individuals with musculoskeletal hip pain. J Orthop Sports Phys Ther. Feb 2008; 38(2):71-7 Level Of Evidence: 2B
¹⁹Hölmich P, Hölmich LR, Bjerg AM. Clinical Examination of atheletes with groin pain: an intraobserver and interobserver reliability study. Br J Sports Med. 2004 Aug; 38(4): 446-51. Level of Evidence: 1C
²⁰Scott A. Lynch, Per A.F.H. Renström; Groin injuries in Sport, Treatment Strategies. Sports Med. 1999 August. 28 (2): 137-144. Level of Evidence: 3A
²¹Almeida MO, Silva BN, Andriolo RB, Atallah AN, Peccin MS. Conservative interventions for treating exercise-related musculotendinous, ligamentous and osseous groin pain. Chohrane Database Syst Rev. Jun 2013 Level of Evidence: 1A
²²Holmich P, Uhrskou P, Ulnits L, et al: Effectiveness of active physical training as treatment for long-standing adductor-related groin pain in athletes: Randomised trial. Lancet 353: 439-443, Feb 1999 Level of Evidence: 1B
²³Machotka Z, Kumar S, Perraton LG. A Systematic Review of the Literature on the Effectiveness of exercise therapy for groin pain in athletes. Sports Med Arthrosc Rehabil Ther Technol. Mar 2009 1(1): 5. Level of Evidence 1A
²⁴Weir A, Jansen JA, Van de Port IG, Van de Sande HB, Tol JL, Backx FJ. Manual or exercise therapy for long-standing adductor-related groin pain: a rondomised controlled clinical trial. Man Ther. 2011 Apr; (16)2:148-54. Level of Evidence: 1B
²⁵Adductor Tendonitits; Groin Squeeze: Physio Advisor. http://www.physioadvisor.com.au/10426550/adductor-tendonitis-adductor-tendinopathy-phys.htmfckLRfckLRfckLRfckLR (accessed on 12 November 2014) Level Of Evidence: 5
²⁶Groin Stretches: Groin Strecht Standing. Physio Advisor. http://www.physioadvisor.com.au/8277563/groin-stretch-adductor-stretch-adductor-flexibi.htm (accessed on 12 November 2014) Level of Evidence: 5
²⁷Hölmich P, Larsen K, Krogsgaard K and Gluud C. Exercise Program for Prevention of Groin Pain in Football Players: a Cluster-Randomized Trial. Scandinavian Journal of Medicine & Science in Sports. Dec 2010 20 (6): 814-821 Level of Evidence: 1B