5.4 .. BIO Injuries to the Spinal Column. In the treatment of spine injuries, it is often necessary to provide some tension along the spinal column to stretch the backbone. One device for doing this is the Stryker frame, illustrated in Fig. E5.4a. A weight W is attached to the patient (sometimes around a neck collar, as shown in Fig. E5.4b), and friction between the person’s body and the bed prevents sliding. (a) If the coefficient of static friction between a 78.5-kg patient’s body and the bed

5.4  .. BIO  Injuries to the Spinal Column.    In the treatment of spine injuries, it is often necessary to provide some tension along the spinal column to stretch the backbone. One device for doing this is the Stryker frame, illustrated in Fig. E5.4a. A weight W is attached  to  the  patient  (sometimes  around  a  neck  collar,  as shown in Fig. E5.4b), and friction between the person’s body and the bed prevents sliding. (a) If the coefficient of static friction between a 78.5-kg patient’s body and the bed is 0.75, what is the maximum traction force along the spinal column that W can pro- vide without causing the patient to slide? (b) Under the conditions of maximum traction, what is the tension in each cable attached to the neck collar?