Speed of Tennis Ball Necessary to Cause Concussion
 

Hey everyone,
I was playing tennis and was struck in the head with a tennis ball pretty hard. My opponent and I were at the net and the ball was lobbed and he volleyed it as hard as he could. Now, I am quite anxious, but I mainly want to know the speed of a tennis ball necessary to cause a concussion. It weights about .06 kg, but my kinetic physics is quite inapproximate, as I'm estimating too many values (like the speed of the tennis ball and the duration of contact with the head).
Any help is appreciated,
Tyler

Hi Tyler,

Does your head hurt? Did you fall to the ground?

I don't understand your question regarding the physics of the incident.

I'd be more concerned about any symptoms.

p.s. I was an athlete when young and was hit on the back of the head with a discus that swung out of the hand of a person winding up.

It was a shock. I fell to the ground. It hurt. I got back up again. I wasn't worried about the weight of the object or the speed of the object or estimating values.

Keep calm and if you have any problems you should see a doctor. It's lucky it didn't hit your eye or something. If it hit your eye it would be more worrying.

I should have clarified. I understand understand it requires somewhere in the neighborhood of 50 g's of acceleratiom to the head to cause a concussion, and I typically evaluate hits to the head by estimating their acceleration to my own head. I can't trust myself to evaluate concussions symptomatically as it get conflated with all my anxiety as of now. That's why I want to know just how fast a tennis ball would have to travel.

I get it. Lots of variables though.

If you use the Search feature you might find some of the older posts. There is one I found from Mark specifically regarding tennis balls.

I really hope you are able to get your anxiety about concussions lessened sooner than later. I hope you're getting some professional guidance about that. Keep working on it. There are many different ways of doing that as difficult as it might seem right now. It's very important for your recovery.

Hi Mark and Laura,
I appreciate your responses, and I understand that my response is largely anxiety driven. As Laura suggested, I am yet to overcome that in spite of the length of time I have been struggling with it. I cannot be sure whether I endured immediate symptoms, but as Mark's copied and pasted questioning of self-analysis suggests, all I may do is continue living and respond to the appearance of any symptoms healthily. At the moment, I am experiencing some mild pain/numbness at the site of impact, some fogginess, tension in the head, and nausea, but it's hard to tell if that is merely the aftermath of a wild bout of anxiety.
For the record, I came up with about 35-40 g's of force to the head using the values Mark provided, which is a wallop of a subconcussive hit, but not concussive for most.
I wish you guys all the best in your day. I always wonder if Mark, and perhaps you, Laura, depending on much you respond, gets tired of responding to these all these posts written in a panic. I know it's a pain, but I of course appreciate the mountain of posts to which you have responded over the years.

Hi Tyler, I hope your head isn't feeling too bad today.

No need to thank me at all. I don't post here so much anymore and just happened to log in when you had posted. I'm on a different time zone so often pop in when the US is asleep.

I have a lot of empathy for people dealing with the anxiety after a concussion.

I've had a few head injuries in my life but one time I slipped down some stairs that had Sisal floorcovering that had worn. I slammed the back of my head into the corner of the wall and ended up with a mild concussion about 15 or so years ago.

The most difficult ongoing physical problem was residual vertigo but my absolute worst problem overall is that I ended up with a total fear of stairs. For years I avoided stairs because I was afraid of falling again. That was coupled with the vertigo so it really made life very difficult going anywhere.

So, long story short, I hope you feel alright today. It's difficult on the internet. There are so many variables as I mentioned and none of us are there with you in person when it happened. e.g. how close you were to the other player when they hit the ball you possibly jerked your head to get out of the way and what part of your head did the ball hit... questions like that. If someone hit my head really hard with a ball I'd probably automatically jerk my neck really hard.

Laura,
I appreciate your sympathy, and its awfully unfortunate that most doctors treating concussion patients cannot exercise a similar degree of empathy, even if it's because they haven't experienced a severe concussion themselves. It's funny that concussions can make us avoid stairs and fear even the smallest bumps, but I honestly feel like I've learned so much about myself and had a greater appreciation for my health that I don't regret getting my first bad concussion, even if it turned my life upside down for a year.

I'm not sure how you feel about your injury, but I hope the 15 years since your injury have been an insightful if not positive experience in your life. Little things like supporting each other makes all the difference, so I really appreciate your concern. It's funny that you mention other members witnessing the event as I've grown reliant on my significant other to describe the events back to me. I'm not proud of it, and my concerns should be directed towards a professional source, but speaking to someone else certainly goes a long way. Even seeing your or Mark's reply made my anxiety levels plummet.