“Novel treatment of muscle weakness following joint injury has sought to develop interventions that can excite the neuromuscular system and allow for more effective interactions between the nerves and muscle.”
Chad and Brent both play the same position for the same basketball team—same practice routine, same strengthening program, same injury prevention program—but Chad is suffering from left patellar tendonitis. Why is Chad injured and not Brent? We have adopted laymen medical terms such as “Runner’s Knee”, “Little Leaguer’s Elbow”, “Tennis Elbow” or “Jumper’s Knee” implying these types of injuries are caused by the activity. But are they? What if Chad’s “Jumper’s Knee” is linked to a brain or spinal cord deficit and not some musculoskeletal dysfunction?
Everything we do —touch, sense, feel, contract, move— triggers an action potential that is sensed by millions of mechanoreceptors, which follows a path to the brain.
The action potential is picked up by peripheral nerves and carried to the dorsal root ganglion cell and travels to the spinal cord.
The impulse goes through the dorsal column nuclei and the impulse is taken to the thalamus in the brain via the spinothalamic tract.
In the brain, this impulse synapses with the ventroposterolateral thalamus and onto the somatosensory cortex.
A motor response is then triggered.
This path is followed every time. Sensory or motor deficits anywhere along this path can lead to injury. Sometimes, as health care providers we get in a rut and look to treat the body part or underlying movement dysfunction. While this practice is not necessarily bad, it might not be what is needed. Correcting muscle imbalance or addressing joint dysfunction may not be the answer. Removing the athlete from activity to reduce overload may not be the answer. Our goal should aim to fix deficits along the neural path. Continue reading →
I have posted on this topic many, many times. Unfortunately, many still revert to antiquated rehabiltiation protocols. Thus, I feel compelled to keep talking about it. If you or a client has knee pain focus on the hip, not the knee. There is so much data out there on linking decreased glute strength to knee pain. A weak or inhibited glute medius is unable to control femoral internal rotation and obligatory knee frontal plane motion. These motions are a primary cause in knee pain – traumatic and acute. Today I discovered two, recently-published, systematic reviews to prove my point.
The first review examined 47 studies which looked at factors causing Patellofemoral Pain Syndrome (PFPS) (1). This review identified decreased muscle strength for hip abduction and hip external rotation as an important factor associated with the cause of PFPS. The pooled data also found increased Q-angle and sulcus angle to be factors – both of which have been linked to muscle imbalance.
The second systematic review was more specific by evaluating gluteal muscle activity – via EMG – and PFPS (2). The authors identified ten studies to be included in their review, with six of these studies considered to be high-quality and eight studies having a score of 8 or higher on the Downs and Black scale. The authors conclude there is moderate to strong evidence linking delayed or short Glute medius muscle activity to PFPS. The authors also state, “If gluteal muscle activation is delayed, frontal and transverse plane hip motion control may be impaired, leading to increased stress on the PFJ and subsequent symptoms associated with PFPS.”
Rehabilitation practitioners should note this when developing rehabilitation programs. Specifically targeting glute weakness and inhibition will limit hip internal rotation and obligatory knee frontal plane motion. Correcting faulty movement patterns will allow for optimal neuromuscular recruitment and joint kinematics, ultimately relieving or preventing pain.
Are you ready to change your rehabilitation program?
Lankhorst NE, Bierma-Zeinstra, SMA, and van Middelkoop, M. Factors associated with patellofemoral pain syndrome: a systematic review. Br J Sports Med. 2013;47:193–206.
Barton CJ, Lack, S, Malliaras, P, and Morrissey, D. Gluteal muscle activity and patellofemoral pain syndrome: a systematic review. Br J Sports Med. 2013; 47:207–214.
Selkowitz, DM, Beneck, GJ, and Powers CM. Which Exercises Target the Gluteal Muscles While Minimizing Activation of the Tensor Fascia Lata? Electromyographic Assessment Using Fine-Wire Electrodes. J Orthop Sports Phys Ther. 2013; 43(2):54-64.