November, 2010

Cardiorespiratory Fitness a Predictor of Death

November 17, 2010

In this blog: 1-Research study "Cardiorespiratory Fitness as a Quantitative Predictor of All-Cause Mortality and Cardiovascular Events in Healthy Men and Women A Meta-analysis" 2-2008 Guidelines for Physical Activity The Running Clinic of Toronto often sends us some interesting articles relating to fitness and running. The latest was an article from JAMA 2009 studying the relationship between cardiorespiratory fitness and mortality and cardiovascular events. As a result of the study, they found an inverse association between cardiorespiratory fitness and mortality and cardiovascular events after a thorough analysis of previous research from 1966 to 2008. In other words, the better your cardiorespiratory fitness, the lower chance of all-cause mortality or cardiovascular events. In this case, all-cause mortality is the total number of deaths in relation to a healthy population. To view the article, click here. Meanwhile, the U.S. Department of Health and Human Services published a guideline for 2008 Physical Activity Guidelins. According to the guideline, "medium activity is 150 minutes to 300 (5 hours) minutes of moderate-intensity activity a week (or 75 to 150 minutes of vigorous-intensity physical activity a week). In scientific terms, this range is approximately equivalent to 500 to 1,000 metabolic equivalent (MET) minutes a week." They also state that: "Studies have examined the role of physical activity in many groups—men and women, children, teens, adults, older adults, people with disabilities, and women during pregnancy and the postpartum period. These studies have focused on the role that physical activity plays in many health outcomes, including: • Premature (early) death; • Diseases such as coronary heart disease, stroke, some cancers, type 2 diabetes, osteoporosis, and depression; • Risk factors for disease, such as high blood pressure and high blood cholesterol; •Physical fitness, such as aerobic capacity, and muscle strength and endurance; •Functional capacity (the ability to engage in activities needed for daily living); •Mental health, such as depression and cognitive function; and •Injuries or sudden heart attacks. The Health Benefits of Physical Activity—Major Research Findings •Regular physical activity reduces the risk of many adverse health outcomes. •Some physical activity is better than none. •For most health outcomes, additional benefits occur as the amount of physical activity increases through higher intensity, greater frequency, and/or longer duration. •Most health benefits occur with at least 150 minutes a week of moderate-intensity physical activity, such as brisk walking. Additional benefits occur with more physical activity. •Both aerobic (endurance) and muscle-strengthening (resistance) physical activity are beneficial. •Health benefits occur for children and adolescents, young and middle-aged adults, older adults, and those in every studied racial and ethnic group. •The health benefits of physical activity occur for people with disabilities. •The benefits of physical activity far outweigh the possibility of adverse outcomes. The idea of fitness and activity resulting in a healthier human being is not new. However, each year, we have more and more research giving us quantitative guidelines to follow to give us the best chance of lowering risk of death and increasing quality of life. Due to advances in technology, we may not necessarily need to worry about how long we live, but how we live in our golden years. Our bodies aren't asking for much. 30 minutes a day, 5 days a week.
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Knee Pain and Running

November 8, 2010

Knee Pain with Running My last blog briefly covered the top 5 running injuries we see in the clinic. Knee pain is at the top of the list. Although there are several different diagnoses we find with runners, I would like to focus on Patellofemoral Pain Syndrome. Patellofemoral Pain Syndrome (PFPS) is pain around the knee cap, usually due to a "tracking" problem as well as the patella (kneecap) compressing on the femur (thigh bone). The patella (train) travels along a groove in the femur (train track) when the knee is bending and straightening. Historically, it has been theorized that the Vastus Medialis Obliquus (VMO- a muscle attaching from inside of the thigh bone to the inside part of the kneecap) was to blame for patellar tracking abnormalities due to it's weakness and the Vastus Lateralis and IT Band (Quad muscle on the outside of the thigh and connective tissue running the length of the outside thigh respectively) dominance and tightness. However, recent research (Powers et al. JOSPT, 2003 and Souza & Powers, JOSPT, 2010) has suggested that we may have had the train and track analogy all wrong. Due to advances in modern technology, we are able to view a dynamic MRI weight bearing. Meaning, we can see how the patella is moving in relation to the femur, weight bearing via an MRI. Or... I should say, we can see how the FEMUR moves in relation to the PATELLA. As mentioned above, it has been theorized that the train moves off the track due to VMO weakness and VL strength/ITB tightness. However, Powers et al. found through a dynamic weightbearing MRI that the femur actually rotates inwardly (internal rotation) under the patella. Meaning, the patella (train) stays it's course and the track moves away from the train. This is significant since it changes how we approach PFPS. Combine femoral internal rotation with tight quadricep muscles, and now you are compressing the patella against a rotating femur which is a recipe for pain and grinding of the knee cap which can lead to chondromalacia of the patella. Now what? Clinically, we do a video analysis of running along with several biomechanical, range of motion/flexibility, and strength tests to determine the cause of PFPS. Through slow motion video, we can see the femur internally rotate in running as well as jumping, landing, squatting, and lunging. We will also determine which muscles are weak and which movements are restricted, thus causing the femoral internal rotation. Shoes, feet, and ankles are also examined as accompanying factors of PFPS.

Example of Dynamic Functional Analysis

 

An example of stride angle

Common Causes Typically, we see a quad dominant behavior in movement and running and lack of Gluteus Maximus and Gluteus Medius activation and recruitment. Tight hamstrings, quads, and hip rotators are often associated findings with PFPS. Less often, we see overpronation dysfunction of the feet and ankles, though gluteal weakness is often a culprit of overpronation. Treatment consists of ART, Graston, Spidertech, rehab/strengthening exercises, and chiropractic if needed. Training and shoe advice are often provided to cover all contributors of PFPS. If you have knee pain with running, feel free to email Dr. Jess at drjess@innersport.com or comment on this blog below. We'd love to hear from you.
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