Structural Balance Part 1
By: Kevin Ensenat
This article is a summation of one of the most important concepts I have learned in my 15 plus years as a strength and conditioning coach and personal trainer. This concept has helped me design and prescribe the most beneficial and successful workouts for each of my clients. Unfortunately, too many coaches and trainers either overlook or simply do not understand how to recognize and/or correct structural balance issues until it is too late.
Structural balance is a term used to describe the proper strength and flexibility ratios between different muscle groups. These ratios dictate how well and efficient a movement occurs, provide joint stability, increase every other facet of training such as, overall strength and power and decrease the risk of injury. Pretty important stuff, huh? Part 1 of this article is written to address the knee and help you get a better understanding of the function and proper training of this joint.
The knee is one of the joints most prone to injury in sports. According to a study conducted at the Center for Injury Research and Policy (CIRP) of the Research Institute at Nationwide Children's Hospital and published in the June issue of The American Journal of Sports Medicine.
“The knee was the second most frequently injured body site overall, with boys' football and wrestling and girls' soccer and basketball recording the highest rates of knee injury. The most common knee injuries were incomplete ligament tears, contusions, complete ligament tears, torn cartilage, fractures/dislocations and muscle tears.
"Knee injuries in high school athletes are a significant area for concern," said Dawn Comstock, PhD, CIRP principal investigator, faculty member at The Ohio State University College of Medicine and one of the study authors. "Knee injuries accounted for nearly 45 percent of all sports injury-related surgeries in our study. Knee surgeries are often costly procedures that can require extensive and expensive post-surgery rehabilitation and can increase risk for early onset osteoarthritis. Without effective interventions, the burden of knee surgeries and rehabilitation will continue to escalate as the number of high school athletes continues to grow."
Researchers also found several interesting gender patterns. For example, while boys had a higher overall rate of knee injury, girls' knee injuries were more severe. Girls were more likely to miss greater than 3 weeks of sports activity (as opposed to less than1 week for boys) and were twice as likely to require surgery. Girls were also found to be twice as likely to incur major knee injuries as a result of non-contact mechanisms, often involving landing, jumping or pivoting. Science Daily (May 23, 2008)
Although, the reasons for knee injuries are too numerous for a single article, in this article I hope to explain and educate you about some of the more common reasons.
One of the reasons women are more prone to knee injuries than men is based simply on biomechanical differences. One such difference is a shorter but wider pelvis in women then men. Many sports medicine experts have linked a wider pelvis to a larger “Q” Angle- the angle at which the femur (upper leg bone) meets the tibia (lower leg bone). This angle is generally degrees greater in women than in men. This increased angle places more stress on the knee joint.
The first major problem leading to knee injuries as far as strength imbalances go is a weak vastus medialis oblique or vmo. This is the small teardrop shaped quad muscle on the inside or medial portion of the knee. This is also called the jumpers muscle. This muscle helps to stabilize the knee and prevent buckling upon landing a jump or change of direction.
The second major problem is weak hamstrings in relation to quadriceps strength. One of the most common problems I see with all of my athletes when they first come in is weak hamstrings and gluteal muscles (butt muscles). Now besides being the most important muscles for jumping, sprinting, hitting, throwing and overall sports performance weakness in this muscle group causes extreme stress between the anterior (front) of the knee and posterior (back) of the knee. This stress over time or sometimes one time can lead to a crippling knee injury.
In addition to just anterior and posterior sides of the joint there is the issue between proper balance between the individual “heads” or parts of each muscle group. The quadriceps, consist collectively of 4 muscles. These are the vastus medialis, vastus lateralis, vastus intermedius and rectus femoris. The function of the quadracep muscles is to extend the knee joint, absorb landing and change of directional forces and to balance forces equally across the knee joint.
The posterior side of the leg is where the hamstrings lie. The hamstrings consist of 3 muscles the semitendinosus, semimembranosus and biceps femoris. The primary function of the hamstrings is to flex the knee as well as extend the hip.
Just like the quadriceps it is very common to see certain muscles of each group be much stronger than the others. This leads to the stronger muscles doing most of the work and increased stress on the weaker muscles causing muscle strains and knee sprains as well as a host of other problems.
The third major problem is flexibility imbalances. The most common are tight illiotibial band, hip external rotators, tight adductors, quads and psoas (hip flexor) muscles. Proper flexibility is very important to overall function, performance and injury prevention. Proper flexibility not only means not being flexible enough in certain muscle groups but also being too flexible in others. Being overly flexible in certain joints or hyper flexible can cause just as many problems as being too “tight” or hypo flexible. Look at it this way, when a muscle is too tight the opposing muscle group must work harder to move a part of the body as well as limit the range of motion and putting undue stress on other muscles and connective tissue leading to pain, poor performance and injury. On the other side of the coin a muscle or joint that is hypermoble allows for too much movement and leads to placing the joint and surrounding muscles into a very weak and vulnerable position. Flexibility can be improved through proper and consistent stretching as well as soft tissue work for adhesion problems. Adhesions are scar tissue built up in muscle from injury, overuse and chronic stress placed on a muscle, joint or bone over time from many of the issues mentioned above.
I hope this article helps parents, coaches and athletes understand the importance of structural balance in training. I know it may seem very overwhelming but this is only a brief overview of the most common issues I see. My goal is to help teach parents, coaches and athletes that there is more to training than just throwing some weight on a bar and doing a few sets or 5-10 reps. To truly help an athlete reach his/her potential it is important to find a qualified strength coach that can identify each athletes specific problems and needs. Once this information is gathered then a specific workout can be designed to address these needs and the overall performance will improve dramatically and the risk of injuries will be minimized! In part 2 of this series I will discuss the shoulder joint.
Rise Up,
Kevin