A spinal instrument includes sensors for measuring a parameter of the muscular-skeletal system. The spinal instrument includes a sensored head region that can be inserted into a spinal region. The spinal instrument comprises a housing, a housing, an electronic assembly, and a flexible interconnect. Housing includes a handle portion, a shaft portion, and a support structure. Similarly, housing includes a handle portion, a shaft portion, and a support structure. Furthermore, housing has a cavity and a lengthwise passage respectively for receiving electronic assembly and flexible interconnect. A sensored head region of spinal instrument includes an assembly stack for measuring load magnitude and position of load on the support structure and the support structure. The flexible interconnect couples the electronic assembly to the sensors.