chutchinson

I want to give everyone a little intro to the Physiology of combat. I believe that all combative programs should spend some time talking about the physiology of combat as it gives students an understanding on what may be happening to them during a fight. For more info I highly recomend "On Combat" by Lt Dave Grossman.

The peripheral nervous system is divided into two parts, the Somatic nervous system and the autonomic system. The somatic nervous system controls all voluntary muscular systems while the autonomic nervous system is the involuntary. The autonomic nervous system is divided into two parts. They are they sympathetic nervous system (SNS) and parasympathetic nervous system (PNS). The SNS is the part that uses energy while the PNS is the part that increases the amount of stored energy. Salivation and the digestive system are examples of PNS processes. During the day your body is in homeostasis. Both are balanced and working in their own way.

The SNS activates in a number of ways: threat perception, fear perception, physical exhaustion and startle response.
During SNS activation a number of things can happen. The body starts to create a number of hormones. One of them is adrenaline. The heart rate will also increase. This increase in heart rate will move the hormones around the body much faster than usual. The rate of respiration will also increase

One big this is vasoconstriction. Basically the blood vessels narrow and it becomes harder for the blood to get to the extremities. One major benefit of this is that wounds may not bleed much at first. This is why after any incident involving an edged weapon or a firearm it is always good to perform a check on your co-workers and have them check you. Just because they aren’t bleeding yet doesn’t mean that they aren’t injured. It’s better to find the wound while the body is still experiencing vasoconstriction rather than waiting for the blood vessels to open up again. Among the disadvantages of vasoconstriction is a lack of blood flow to the extremities. This may inhibit an officer’s ability to perform fine and complex motor skills.

Another thing that can occur during SNS activation is perceptual narrowing. The most common types are tunnel vision and auditory exclusion.

One instructor explained tunnel vision like this. “Men, remember the last time a well endowed female walked past. What did your brain focus on? Her chest...Now what colour was her hair? What was she wearing? You probably couldn’t remember because your field of vision narrowed so much that you didn’t register anything other than her chest. The same thing can occur in a fight. The brain gets so caught up in looking at the threat that it misses so much more information.” I think that sums it up nicely.
Auditory exclusion can also be fairly common. Did you ever have a time when you were in a fight and you were told later that people were calling you on the radio...only you swear you didn’t hear it. Or, you were so focused on your radio that you didn’t hear the person next to you? These are both examples of auditory exclusion.

During SNS activation many PNS processes will shut down. The body begins to realise that the PNS functions are not necessary to its survival. Salivation may shut down resulting in dry mouth. Meanwhile the bladder and bowel systems may shut down. This may result in a loss of bladder and bowel control resulting in urination and defecation. This isn’t mentioned in many combatives program manuals or even in class because the instructors find it embarrassing (In my mind this is unacceptable because if it occurs then our officers may not understand why and think that something is wrong with them). All of these are perfectly normal processes.

Just because these things can happen it doesn’t mean that they will. I have been involved in incidents where I experienced physiological changes and others where I have experienced none. Each person is different. Each officer’s response will be different. If you ever teach this to other officers make sure you tell them that it is okay of any of the above happen. It is also okay if none of the above happens. As I mentioned everyone is different. Please be mindful of that.

There are three energy systems that the human body will rely upon in a confrontation. The first is the ATP/PC. This is bundles of energy in the muscles that allows you to perform at 100%. Unfortunately this burns out after about 10-15 seconds. The body then relies on the Lactic Acid System. Over the course of about a minute the amount of energy the body can put out will continue to reduce. Finally we come to the Aerobic system. This is the bodies ability to get energy through breathing. As long as the officer can breath they still have some energy. Again this will reduce over time. Most studies suggest that by the time the officer is at the aerobic system they are only hitting at about 30% of their maximum.

Those of you that are keen eyed will notice that I haven’t mentioned the relationship between heart rate and performance. The “Inverted U Hypothesis”. The reason is this. I am not sold on it. Does heart rate effect performance? Yes. Is it a hard and fast rule? No. Again no two officers will respond alike. I could get your heart rate up to 180 bpm and you might still be able to perform fine motor skills. Something that, according to the hypothesis is impossible. Remember everyone is different. No two people will react and respond the same.

Stay safe,

Chris