The point of a joint in which the proximal limb segment moves relative to the distal limb segment in all three planes: Sagittal (flexion/extension), frontal (ab/adduction), and transverse (internal/external rotation). When referring to the knee joint, the proximal segment is the femur and the distal segment is the tibia/fibula.

Last

When referring to shoes, it is a form made of wood, plastic, or metal roughly in the shape of a human foot around which the upper part of the shoe is built. The last provides the size and fit of the shoe. Footwear companies’ lasts are highly proprietary.

Proprioception

The perception or sensing of your limbs in space (orientation) during movement of the body. Specifically in running, proprioception allows your mind to learn, with each step, from the effect of each movement and then adjust your limbs accordingly for future movements.

Prospective research

A study in which similar people are followed over time, waiting for an outcome to occur. People who have a positive outcome are compared to people who have a negative outcome over time to see what is different between the two groups to explain how these factors affect the rate of a certain outcome.

Example: Study of 50 runners between ages 20-25 who run 40-50 miles a week. All are similar in age and miles. An initial analysis of these runners would be conducted (collect weight, height, shoes running in, kinematics of running, etc.). After one year, all runners who had Patellofemoral Pain Syndrome would be compared to the runners who did not to see if these people differed in weight, shoe worn, knee angle, and so forth. The variables that differ between the two groups are possible risk or prevention factors for that injury.

Retrospective research

A study that looks back in time and examines a population that has a given condition (test group) with a similar group of people that does not have the condition (control group). Due to confounding factors, these studies cannot prove causation but provide causal links.

Example: Medical records are examined to find 30 runners who had a patellofemoral pain over the past three months. Determine their age, how many miles per week they run, height, weight, etc. so that a control population matching these criteria can be established. (The control group would match the injured population in a set of variables and no history of Patellofemoral Pain Syndrome.) The two groups are then tested and compared. If knee flexion angle is less in the injured population versus the control group, you would say that there is a causal link to that injury. However, since the person is already injured, and you don’t know anything about him or her before the injury, you can’t determine cause because the difference may be a result of the injury and not a cause of the injury.

Shod

Wearing footwear

Unshod

Without footwear (i.e. barefoot)