- Physiotherapists have dismissed claims that Kirk likely suffered genital damage
- Could be surgery necessary to repair the torn tissue in his abdomen
- READ MORE: Italian man's testicle dislocates and swings INSIDE his abdomen
Viewers of Monday night's Jacksonville Jaguars game no doubt jolted at the sight of wide receiver Christian Kirk falling to the ground in pain.
In a passionate attempt to catch the ball, Kirk fell backwards with his legs open and was then seen limping off the field.
He has been sidelined since then due to the injury – and head coach Doug Peterson said Kirk's injury will likely require surgery.
But it was not clear exactly which part of his body was injured.
And viewers who watched the drama unfold were most intrigued by where his hands ended up once he fell: his crotch.
Christian Kirk appeared to strain his groin muscle while grabbing a catch early for the Jaguars
X, formerly known as Twitter, was full of theories about what happened, with many suggesting that Kirk was suffering from a painful genital problem called testicular torsion.
This happens when the testicle twists and twists the spermatic cord that supplies blood to the scrotum, causing extreme pain. The problem requires corrective surgery to prevent permanent damage to the genitals.
Recovery time can take up to two weeks.
“Testicular torsion in play,” tweeted personal trainer Jeff Mueller, who has 23,000 followers on X. Meanwhile, another user wrote: “TESTICAL TORSOR! I think Christian Kirk twisted a nut in the pocket while he turned that ball on!'
However, reports published on Tuesday morning suggested the real problem was in fact a core injury.
So what is the truth?
Speaking to DailyMail.com, experts say testicular torsion is unlikely to be the problem.
Instead, it's likely that Kirk suffered a core muscle injury; although this can also affect the pelvic area.
The abdominal and thigh muscles are attached to the same spot on the pubic bone, but pull in opposite directions. Force can tear the attachment, causing a core muscle injury.
A core muscle injury, also called a sports hernia, is a painful soft tissue injury that occurs in the groin area.
It usually occurs when a sudden change of direction is required or when a player makes intense twisting movements.
There will usually be severe pain in the groin area at the time of the injury, which will improve with rest.
A sports hernia does not cause a visible bulge, as a normal hernia does.
It may require surgery to repair the torn tissues.
Karena Wu, a New York physical therapist, told DailyMail.com that Kirk may have “pulled something off,” where the muscle tendon separates from the bone.
Ms Wu said: 'On his last step it could have been an overextension, or something to the effect that his muscle wasn't ready to absorb that force and that's what caused the injury.'
If he undergoes surgery, he will likely be off the field for six months.
“It is very common in football to sustain non-contact soft tissue injuries,” Wu says.
'When distracted, it is possible for the upper and lower body to be pulled in different directions, creating a damaging pull on the soft tissue.'
She explained that Kirk would likely experience pain, inflammation and swelling in his groin area.