Exercise-induced Ischemia and the Influence of Pain Modulation in a Nerve Growth Factor (NGF) Model

Interaction Between NGF and Exercise-induced Ischemia, and the Influence of the Pain Modulating System in a Prolonged NGF Sensitized Muscle.

The purpose of this study is to investigate responses of pain and the maintenance of mechanical muscle hypersensitivity following an acute exercise-induced ischemic condition repeated over time in a prolonged NGF-sensitized muscle. Additionally, the influence of the pain modulating system on prolonged NGF muscle hypersensitivity caused by peripheral mechanisms and central mechanisms will also be investigated.

The hypothesis is that an ischemic conditioning in a NGF-sensitized muscle is able to facilitate pain responses and that over time the pain modulation system is responsible for a subsequent reduction in muscle sensitivity towards mechanical pressure and a decrease in pain intensity following a period of NGF-induced muscle hypersensitivity.

Inclusion Criteria:

• Healthy and pain free volunteers

Exclusion Criteria:

• Pregnancy
• Drug addiction defined as the use of cannabis, opioids or other drugs
• Previous neurologic, mental illnesses, or psychiatric diseases.
• Past history of chronic pain in the musculoskeletal system (muscle, joint, cartilage, connective tissue)
• Participation in other pain trials throughout the study period
• Lack of ability to cooperate
• Taking any analgesic 24 hours before the injections
• Performing any strenuous leg exercise through out the study period causing sore muscles