It may be lost in the long-running discussion about concussions, but the NHL is suffering an epidemic of knee-on-knee hits, which are up more than 70 percent compared to last year.

To compile my list, I read through 1000 results from Google searches for the phrase "knee on knee", 500 from between August 1, 2010 and July 31, 2011 and 500 that were published since August 1, 2011. This might not be quite comprehensive, but it is probably pretty close. Here's what I found:

There have been 19 knee-on-knee hits so far this year, up from 11 last year.

Pittsburgh is now by far the most frequent offender, with six violations. Edmonton is second with three, and no other team has more than two.

Pittsburgh may be the epicenter, but the illness has spread across the region: 21 of the knee-on-knee hits were delivered by Eastern Conference teams, versus only 9 from the West.

In two years, only one knee-on-knee hit (Kevin Porter's hit on David Booth) resulted in a suspension, and only one other (Adam McQuaid's hit on Nick Foligno) drew a fine.

Knee-on-knee hits were infrequent early in the season -- in the two years combined, there were only three that occurred before December 1. There were 13 in December or January and 14 after February 1.



Players who average less than 12 minutes of ice time per game get about 13% of the ice time, so you might expect them to have delivered or received roughly four of the 30 knee-on-knee hits by random chance. Those players actually delivered seven of the knee-on-knee hits and received only one. Similarly, forwards who average under 0.2 points per game delivered seven knee-on-knee hits but did not receive any. Whether it's because they are cheap-shotting goons or because they get caught out of position, the less-skilled players are much more likely to deliver a hit than you would expect given their share of the ice time and much less likely to receive one.

Like head shots, knee-on-knee hits are dangerous and can come from either dirty play or from accidents owing to the speed of the game. The league has taken affirmative steps to try to reduce the number of hits to the head and resulting injuries, but they haven't done the same for knee-on-knee hits.

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With only one suspension and one fine in the last two years, is it any surprise that the number of knee-on-knee hits has increased sharply? Is it any surprise that the goons are dishing them out and the stars are receiving them? Is it any surprise that at least one team is showing signs of incorporating them into their style of play?

At some point, the league is going to have to step in and take measures to discourage this reckless, dangerous play. Let's just hope they don't wait until knee-on-knee hits have ruined as many careers as concussions have.

Table of knee-on-knee hits found in my Google searches; let me know if you know of some that I missed.