Fixing the Flaws: A Look at the Three Most Common Biomechanical Weak Links Associated with Common Injuries


Weaknesses and muscles tightness can be the cause of considerable disability and injury among many people. They can be caused by past injuries, accidents, prolonged poor posture etc. There are several categories of weak links over which a strength and conditioning specialist / physical therapist can have profound impacts. These impacts can favorably reduce the risk of injury and improve quality of life. In my experience, these are the three most common biomechanical flaws associated with common injuries.


Core Weakness and Low Back Pain

Low back pain (LBP) is one of the two most common types of disability affecting individuals in Western countries. Most Americans (80%) will have back problems at some point during their lifetimes.

Unfortunately, you cannot snap your fingers and get rid of chronic low back pain, it needs to be address to the source, otherwise it will come back over and over again. Many studies have shown that core stability exercises are an important component of rehabilitation for LBP but what are they? What do they have to do with your back? The core can be thought of as a cylinder of muscles around the inner surface of the abdomen. There are 4 main muscle groups considered: the transverse abdominus, multifidus, diaphragm and pelvic floor. Imagine a can of soda which represents your torso from below your chest to the hip bones. The pressure in the can should always be maintained in order to stabilize your back. When the Transversus Abdominus contracts (which is localized deep in the front), The diaphragm contracts and pushes down into the abdominal cavity, which combined with the resistance created by the pelvic floor, and a contraction of the entire abdominal wall, increases the pressure in front of the spine. The pressure from the front is counteracted by contraction of the lumbar muscles and the spine is fully stabilized. Having a strong and healthy core significantly decreases your chance to suffer from low back pain by stabilizing the spine.  If your back pain limits your activities in any ways, and they persist more than 1 day, come see one of our specialists at Naples Personal Training.  

 Weak Rotator Cuff and/or Scapular Stabilizers             

The Rotator cuff is a common name for the group of 4 distinct muscles and their tendons that provide strength and stability to keep the head of your upper arm bone (humerus head) firmly within the shallow socket of the shoulder during shoulder movements. If there is imbalance between shoulder muscles, impingement can occur and cause serious injuries. There are 2 types of muscle imbalance that can cause shoulder impingement. First, imbalance between the rotator cuff and the deltoid muscle. The pull of your deltoid and the pull of your rotator cuff must be the same. The deltoid muscle is responsible to elevate your arm, it’s pulling up. On the other hand, the rotator cuff muscles pull the humeral head towards the socket. If the balance between the rotator cuff muscles and the deltoid is off, the deltoid will overpower the cuff muscles and the result will be a superior translation of your upper arm bone. Second, you can have an imbalance between your internal and external rotators (front and back rotator cuff muscles) which are the subscapularis and infraspinatus muscles. Instead of having the humerus head spinning into the joint, the result is an anterior glide of the humerus head causing impingement during arm elevation. You want to have all the muscles working together to keep the ball in the socket during overhead movements. The most common signs and symptoms of rotator cuff injuries are shoulder pain at night, pain when lifting and lowering your arm, weakness when lifting your arm and pain slightly below the shoulder. Briefly, rotator cuff muscles weakness can lead to impingement and eventually rotator cuff tear. However, studies have shown that around 75% of cases, surgery can be avoided with proper exercises. Make sure to visit our office if you have one or more of these symptoms!

Weak Neck Musculature and Scapular Muscles / Tight Upper Trapezius and Pectoral Muscles

Computer use or poor sitting posture over years lead to a change in posture, a forward head and rounded shoulders. This posture results in inhibition of a back muscles call lower trapezius which is often associated with inhibition of the deep neck flexors (muscles deep in the front of your neck) and shortening of the pectoral muscles, upper trapezius, and levator scapulae (shoulder blades elevator muscle). In addition, studies showed that rounded shoulders or forward head posture can decrease the space between the acromion (bone that connect your collar bone to your shoulder blade) and the rotator cuff muscles thus, increasing the risk of rotator cuff injuries during overhead movements. A posture assessment by our professional is the best way to determine if your posture needs to be fixed. 

Closing Thoughts

In my experience, one or more of the aforementioned three biomechanical weak links is present in almost everybody. Identifying biomechanical weak links is our priority number one during initial evaluation when you come at Naples Personal Training. We will make sure these flaws don’t limit the way you move, feel and perform. Call us Now! Don’t wait until it’s too late.


Dave Lessard, PT, MPT