Ralph Cornwell

Undergrad From University of Maryland/Radford University Va
Masters of Science from Virginia Tech
Doctor of Philosophy -Science Virginia Tech Completion Date 12/10

Former Strength Coach
Radford University
University of North Carolina at Greensboro
United States Military Academy at West Point
North Carolina Agriculture and Technology State University
West Montgomery High School, NC

Served as Sport Performance Director and Owner of 2 Sports Performance Facilities 1 in Blacksburg, Va, the other in Greensboro, NC.


The first thing you do with athletes that play contact sports is train their necks. Sometimes You Have To Do The Math!

Small changes in strength and surface area do have a profound effect on deflection rates, thus creating a stronger cylinder.

Simple comparison of how two cylinders of a different diameter, one 6", and the other 8", support a given load:

Case - Constant stiffness across diameter of cylinder

Assumptions – Applied load is normal to and evenly distributed over top surface

Cylinder is resting on a surface with infinite stiffness 

 Cylinder 1 – Diameter = 6 in. 

                   Length = 6 in 

                   Stiffness =100 lb/in/in2

 Cylinder 2 - Diameter = 8 in.

                   Length = 6 in

                   Stiffness = 100 lb/in/in2 

 Applied Load:  100 Lbs. 

Deflection of cylinder 1:
                Area = Pi * r2 = Pi * (3in) 2 = 28.27in2
 Deflection = Pressure/Stiffness = (100lbs/28.27in2) )/(100lbs/in/in2 ) = 0.0354in

Deflection of cylinder 2:
                Area = Pi * r2 = Pi * (4in) 2 = 50.26in2
 Deflection = Pressure/Stiffness = (100lbs/50.26in2 )/(100lbs/in/in2 ) = 0.0199in 

This indicates that for two cylinders with the same properties supporting identical loads, a reduction of deflection of 43% is realized by increasing the diameter by 25%.