Over the weekend it was learned that Sidney Crosby was diagnosed with an apparent neck injury involving the C1 and C2 vertebrae, an injury that went unnoticed until Crosby sought second opinions from doctors in Utah and California.

While great strides have been made to diagnose concussions, little attention has been paid to the neck, which can take substantial stress from head trauma. We spoke with Dr. David Harper, a chiropractor and director of Mosaic LifeCARE & SportsCARE Institute in Toronto for insight on Crosby’s injury and its possible relationship to concussions.

Q: What are the C1 and C2 vertebrae?

A: The C1 and C2 are the top two cervical vertebrae in the neck, right under the base of the skull, and they're the most different of all of the vertebral segments within the spine. The shape of them, the arrangement, the type of bones that they are — they are the most dynamic. The rest of the spinal vertebrae are similar except for size. There's a typical style of what the vertebrae looks like as a bone, but the top two are the most unique compared to the rest of the spine.

Q: What does that mean for people who have their C1 and C2 vertebrae injured?

A: There’s a lot of activity up there, there’s a lot of neurology, there’s a lot of muscularity, there’s fine small muscles that help to manage rotation of the head, which is where a lot of the rotation in your neck occurs. And as the head rotates on the neck, a lot of it happens in that upper cervical area. It’s a very charged area with unique dynamics. The cord comes out of the skull from the brain at that area. There’s a lot of joint receptor feedback in that area of the spine that help with balance and perception of body motion, and knowing where the body is in space. There are nerve centres in that region that affect vision and hearing and other functions called the cranial nerves that may also experience impact.

Q: Could you see a relation between a neck injury and concussions?

A: A concussion injury has traditionally been restricted to comments around the brain. In my opinion, a head injury is never unique to the rest of the spine. There’s a cascade of stress that can happen down the spine. Nothing is not connected — everything is interconnected. It’s not unique and separate. You can’t take the head off the spine, give it a whack, put it back on and say you’ve just got a head injury. You can’t have one without the other. This has been my contention in clinical practice when I work with young athletes, because, while you can have a concussion to the brain, what has been ignored until now has been the relationship to the whiplash that occurs in the neck when the head gets contacted and then abruptly stopped in any form.

Q: What kind of problems do neck injuries create?

A: It can be dizziness, it can be challenges in balance, it can be neck pain, it can be headaches, it can be consequences to any of the cranial nerves, vision. It can be any of those.

Q: Those sound a lot like concussion symptoms.

A: They can, and this has been the challenge. In my clinical practice, we have a difficult time trying to communicate that because it’s difficult to see the neck. You can’t see it because it’s inside your skin, but it’s completely consistent with brain injuries because it’s all part of the cord. It’s all part of the central nervous system.

Q: Have there been any substantial links to spinal injuries and concussion in your practice?

A: I haven’t seen any research on that, to tell you the truth. I just know that clinically when I have a young athlete — which is typically my passion area — I don’t distinguish between there being one or the other. It’s a complete neck-head injury complex. You can’t have one without the other, in my mind. That’s the way I treat it clinically, and that’s the way I’ve been trained to treat it.

Q: What’s the healing timeframe for an injury like that?

A: It depends on the person, and it depends what the injuries are. I mean, there are ligaments that hold your neck together. There are ligaments that hold your skull onto your spine, and just like you can have a ligament injury in the knee with knee trauma, you can have an injury to the ligament in neck trauma. For the longest time I’ve been trying to challenge very different communities to consider such a technology as dynamic motion X-ray, which I don’t have, but I have samples of it and it’d be a dream to have it in my clinic. But dynamic motion X-ray demonstrates ligament weaknesses and fractures that cannot be seen all the time with MRIs, CTs and X-rays.

Q: What can happen if it heals incorrectly?

A: Like everything else, it affects optimal performance. If a fracture doesn’t heal correctly it affects the performance of that area that’s been fractured.