2013-2014: Year of the groin injury?

Groin injuries have been extremely prevalent in the NHL this season, especially amongst goaltenders. NHL goalies have always been prone to hip and groin injuries due to the butterfly style of play, but it's insane how many netminders have missed time this season due to an injury of the groin. 17 out of the 30 NHL clubs have had at least one player miss time this season due to a groin injury, totaling in 37 players overall. This doesn't include players that missed time with undefined or undisclosed 'lower-body injuries.' Listed below are prominent NHL players have have missed time this season due to a groin pain or a groin strain:

Team	Player	Games Missed
Anaheim Ducks
Boston Bruins	Adam McQuaid (D)	8
Buffalo Sabres
Calgary Flames
Carolina Hurricanes	Anton Khudobin (G) Cam Ward (G)	32 10
Chicago Blackhawks	Corey Crawford (G) Nikolai Khabibulin (G)	10 8
Colorado Avalanche
Columbus Blue Jackets	Sergei Bobrovsky (G) Matt Calvert (F)	14 Day-to-day (N/A)
Dallas Stars	Ray Whitney (F) Kari Lehtonen (G)	5 5
Detroit Red Wings	Stephen Weiss (F) Jonas Gustavsson (G) Darren Helm (F) Pavel Datsyuk (F) Danny DeKeyser (D) Daniel Alfredsson (F) Gustav Nyquist (F)	6 4* N/A 2* 1 5 3
Edmonton Oilers	Richard Bachman (G) Corey Potter (D) Justin Schultz (D) Ryan Smyth (F) Dennis Grebeshkov (D)	16 6 8 6 8
Florida Panthers	Tim Thomas (G) Scott Gomez (F) Sean Bergenheim (F)	16 8 N/A
Los Angeles Kings	Jonathan Quick (G)	24
Minnesota Wild
Montreal Canadiens	Max Pacioretty (F)	N/A
Nashville Predators
New Jersey Devils	Cory Schneider (G) Patrik Elias (F)	7 N/A
New York Islanders	Evgeni Nabokov (G)	11*
New York Rangers
Ottawa Senators	Jason Spezza (F)	1
Philadelphia Flyers
Phoenix Coyotes
Pittsburgh Penguins
San Jose Sharks
St. Louis Blues
Tampa Bay Lightning
Toronto Maple Leafs	Joffrey Lupul (F)	7
Vancouver Canucks	Roberto Luongo (G) Dan Hamhuis (D) David Booth (F)	3 N/A 8
Washington Capitals	Brooks Laich (F)	14
Winnipeg Jets	Zach Bogosian (D) Mark Stuart (D)	15 1
* - Currently on IR or injured	N/A- Unable to obtain

GROIN STRAINS - THE INJURY

Groin strains are a common sports-related injury. Treatment depends on the severity of the strain. 32% (12/37) of the groin injuries that have occurred in the NHL this season have been sustained by goaltenders which can be attributed to the butterfly style of goaltending. In the video below, Tim Thomas of the Florida Panthers injures his groin on a right pad save, most likely due to an over-extension.

A groin strain is it's simplest form is a partial or complete tear of the small fibers of the adductor muscles. The adductors are a group of muscles located on the inner side of the thigh, attached along the femur. The adductor longus, adductor brevis, and adductor magnus are three powerful muscles of the adductor group which originate at the pubis (lower portion of the pelvis) and terminate in attachments at the inner side of the knee. These ribbonlike muscles' primary action is adduction of the thigh, which is essentially the movement of pulling the legs back towards the midline. When you're walking , your adductor muscles are used in pulling and swinging your lower limbs towards the middle to maintain balance. Adductors also aid in actions such as squeezing the thighs together, and rotation and flexion of the thigh. The adductor muscle group is pictured below: 

A groin strain can be caused by a variety of actions. There are also several factors that may increase an athlete's chances of developing a groin strain. These factors include a previous strain or groin injury, muscle fatigue, and tightness in the groin muscles due to not stretching properly. 

A rupture or tear of the adductor muscles usually occurs when sprinting, rapidly changing direction, or in swift movements of the leg against resistance (kicking a ball, making a kick save, etc.). This occurs because the adductor muscles are being stretched past a threshold or  beyond the amount of tension they can withstand. Additionally, if the groin muscles are suddenly put under stress when not prepared or if they receive a direct blow, the muscles can be damaged. 

MRI image showing partial-thickness tear isolated to the right pectineus muscle. (Koulouris)

Overusing the adductor muscles over time can result in adductor tendinopathy, a common but infrequently recognized cause of chronic groin pain. Muscle strains tend to occur at the myotendinous junction, or the site of connection between tendon and muscle. Muscle strains typically occur after a single traumatic event. However, tendinopathy injuries don't occur after a single event, it is a chronic but progressive pain that a consequence of overuse and aggravation resulting from athletic activity. Physicians should suspect adductor tendinopathy in cases of going pain with localized tenderness, weakness, and unilateral pain and when the patient complains of groin pain with quick bursts of activity. The diagnosis of adductor tendinopathy is made after a physician/speciliast has reviewed the patient's history, examined their muscles, and then confirms it via MRI (shown below). 

Arrows point to an intense bright signal within the bone marrow. 

This signal is indicative of focal marrow edema, an indication of inflammation. (Avrahami and Choudur). 

DIAGNOSIS 

Diagnosing groin pain can be extremely difficult. Below is a table depicting pathological diagnoses of muscles and their related symptoms.

Symptoms of a groin strain include but are not limited to:

• Pain, stiffness and tenderness in the groin area
• Weakness of the adductor muscles
• Bruising in the groin area
• Popping or snapping sensation as the muscle tears

To diagnose a groin strain, a doctor will need to complete a physical exam. If severe damage is suspected, the doctor may order MRIs to accurately diagnose the strain. During the physical exam, the doctor will complete three steps shown in the video below:

• Observation and palpation: taking a close look at the affected area, observing for swelling and bruising, also if the patient has postural abnormalities when standing or walking. 
• Range of motion: during this step, the range of motion at the hip join, into abduction (moving the leg out to the side) and adduction (moving the leg inwards) will be tested. This provide information about the tightness of the muscles and if stretching the muscle causes pain.
• Resisted muscle tests: adduction will be tested against resistance, causing the muscle to contract. If the patient has a groin strain, it will be painful. 

The doctor will also need to determine the severity of the injury. There are three grade of groin strains:

• Grade 1: A minor or micro-tear with some stretching with less than 10% of the fibers of the muscle being damaged. Grade 1 strains may only appear once an athlete stops exercising, the groin will feel tight and tender to touch.
• Grade 2: a moderate or partial tear of the muscle fibers, ranging from 10 to 90% of fibers torn. The patient will feel a sudden sharp pain in the groin area during exercise and the muscles will tighten. 
• Grade 3: the most serious form, involves a partial or full rupture of the muscle fibers (complete tearing). The patient will feel a severe pain and be unable to contract the muscles or squeeze their muscle together. Swelling and bruising on the inner thigh will occur. 

RECOVERY

Recovery time depends on the severity of the strain. The first thing a doctor will recommend is rest, the muscle needs time to heal. Additionally, an ice pack should be applied to the affected area for up to 20 minutes, four times a day. Some doctors will provide pharmacological treatment, including prescription pain relievers or anti-inflammatory medications (ibuprofen). 

Once the athlete is ready to return, stretching is imperative along with heat packs. Before stretching, athletes should apply heat to the affected area to help loosen the muscle. Stretching should progress in levels, from gentile stretching to more active stretching. Athletes should stop if they feel any pain. Once the pain starts to go away and the doctor clears the athlete, strengthening exercises will begin to help recover the muscles back to their baseline strength. 

DISCUSSION

Groin pain in elite athletes is a common yet challenging diagnostic dilemma for physicians. Groin pain accounts for approximately 5-18% of all athletic injuries and is estimated to account for 10% of all hockey injuries (Syme et al.). Groin injuries are often very difficult to manage as well, as they are often disabling, not allowing an athlete is exercise or walk very much. Recent discoveries in diagnostic imaging has helped the ability to diagnose groin injuries accurately. 

So why the increase in groin injuries this season? Anti Raanta, the Blackhawks backup goaltender, said the smaller pads in the NHL this year may be a cause. He was quote saying "Maybe a little bit, you just have to try to put the knees so tight together, try to block all the holes that you have, it's a little bit harder now." This is an interesting theory, as the butterfly technique is prone to groin injuries to begin with, but with the smaller padding, goalies might be overextending themselves to cover the 5-hole. Bill Ranford, a former NHL goaltender and currently the goalie coach for the Kings said he's noticed the increased amounts of goalie injuries this season but doesn't believe it's due to the smaller sized pads. Ranford believes the compressed Olympic schedule is a bigger culprit. 

Both the compressed schedule and limited pad sizing can definitely be factors or contributors to the increase in groin injuries. However, it's impossible to say for sure. In fact, many goalies (who got injured) did not change their pad sizing. However, it's understandable that it is something that goalies think is affecting them. Several goalies believe it's affected their play and the amount of goals they've allowed, however, there hasn't been much of an increase in goals-per-game in the NHL this season. Team physicians and trainers should explain the importance of stretching, and should also pre-screen players before the season starts to see if they are susceptible to groin injuries (injury history, skating strides, etc.). 

SOURCES

Avrahami, Daniel and Choudur, Hema. Adductor tendinopathy in a hockey player with persistent groin pain: a case report. J Can Chiropr Assoc. 2010 December; 54(4): 264-270. 

Koulouris, George. Imaging Review of Groin Pain in Elite Athletes: An Anatomic Approach to Imaging Findings. American Journal of Roentgenology. 2008; 191: 962-972. 

Syme G, Wilson J, Mackenzie K, Macleod D. Groin pain in athletes. Lancet 1999; 353:1444.