Why should you be training the Inferior Temporal Gyrus for your ACL patients
ACL injury is prevalent in athletics. Not only are there immediate changes once the injury occurs, but there’s substantial evidence that there are long term changes associated with an ACL, including: osteoarthritis, alterations in gait, changes in body awareness and psychology, and weakness, as well as increased risk of further musculoskeletal injury compared to non-injured individuals.
Even more studies have reported unresolved neuroplastic changes after injury, reconstruction, and rehabilitation that may limit function and return to sports participation. There has been a large focus in the past decade on creating preventative programs and limiting exposures to potential injury through conditioning and body awareness. However, decreased body awareness is inevitable with ACL injury.
Trauma to the ACL has been shown to modify how the nervous system processes the interactions between vision and sematosensation. The loss of previously recognized reflexes and gama motor neuron drive to prepare the CNS function to engage appropriately may require “up-training” of other systems, such as increased utilization of visual feedback, to maintain the required sensory input for motor control.
Recently in JOPST, Dustin Groomes, MEd, ATC, CSCS, from The Ohio State University discussed the importance of understanding the changes in body systems and neuroplasticity after ACL injury. Groomes describes how training the biomechanical factors of the ACL injury may not address all the physiologic consequences. But the capacity for neuroplasticity after injury and during rehabilitation can present an opportunity to close the gap by targeting a broader spectrum of sensorimotor function during neuromuscular training. This can be captured by the non-contact (majority) ACL injury. Generalizing the breakdown of the typical action is:
“a failure to maintain knee neuromuscular control while attending to an external focus of attention under highly complex visual stimuli, variable surfaces, movement planning, and decision making, during classically an open environment.”
In this changing environment, the sensory system’s three main afferent pathways –vestibular, visual, and somatosensory – provide complex integrated information. This is rapidly acquired and processed to produce efferent neuromuscular control to maintain adequate stability and control. The interaction between vision and somatosensation is particularly critical for motor control during environmental interaction. This interaction is compromised even after ACL reconstruction. The ACL receives nerve fibers from the posterior articular branches of the tibial nerve. These fibers penetrate the posterior joint capsule and run along with the synovial and periligamentous vessels surrounding the ligament to reach as far as anterior to the infrapatellar fat pad. Disruptions in this input yield immediate changes in neuroplasticity and can lead to mechanical changes and compensations that may not be properly or fully rehabilitated with typical training that focuses solely on biomechanical changes and strength gains.
The loss of ability to rely on the body’s typical reflex afferent inputs may require “up-training” of supplementary mechanisms such as increased utilization of visual feedback to train and maintain required sensory inputs for motor control.
Groomes further states that individuals in his fMRI studies demonstrated increased activity in the posterior inferior temporal gyrus. This area has been linked to many cerebral functions, but may primarily be involved with visual processing of movement. This area must work together with the hippocampus to create an array of understanding of the physical world. The information received in this area is sent to the Primary Visual Cortex (V 1) for processing, determining the outputs from the Motor Cortex (M 1). The increased activity in this area post ACL injury may suggest that there is an increased utilization of visual processing and motor planning for movement simultaneous with depression of the somatosensory function of the ACL previously discussed.
Simply put, the body is nothing if not adaptable, even in ways we don’t fully understand yet. But it seems that if we injure our ACL, the brain automatically changes its preference to more visual based inputs to assist in making decisions for motor control. What about those who aren’t injured yet? On the flip side of that coin, in 2007 Swanik reported initial findings of decreased visual reaction times and processing speeds as predictive of ACL injury. Perhaps we need more visual-based processing and challenges during our preventative strategies as well?
This begs the question. What are we doing for enhancing visual feedback for our ACL or currently healthy clients? How are we up-training them visually in the attempt to prevent overload in the athletic environment? If we know they can’t feel the knee like they used to – literally – how can we impose a greater demand on vision to help adapt not only their body but their brain?
Here are a few tips on how you can start addressing this need with your clients:
1) Start changing our cues and attention to an External Focus.
2) Ensure that we are challenging our clients in an open environment as soon as it is safely possible, performing dual tasks frequently.
3) Consider giving yourself and the client immediate visual feedback during skill training early in rehabilitation with a device such as the Motion Guidance Clinician Kit https://www.meyerpt.com/motion-guidance-clinician-kit
4) Consider taking visual feedback away at times during advanced mechanoreceptor training exercises to continue to challenge the body with different inputs. This might be particularly challenging for the client on altered surfaces or to advance already mastered skills.
Hopefully this information has stimulated your own approach to rehabilitation of this challenging population. We need to be aware of utilizing all possible body systems to maximize the ability of our clients to be ready to return to their best potential in their athletic or work environments.
If you’d like to learn more, please tune in for the webinar below:
Motor Control Deficits and Return to Play Considerations in the ACL Population
Thursday October 5th
1:00 PM EST
Eric M. Dinkins,
PT, MSPT, OCS, Cert.MT, CMP, MCTA, CCI
This webinar reviews the concepts of Motor Control, motor learning and retention, and return to play considerations for the ACL injury population.
Learn easy, practical solutions for patients and clients:
- Introduction to Motor Control and systems involved
- Review of the literature regarding learning and retention strategies
- Review of the literature on Return to Play testing
- Introduction into use of visual feedback and the Motion Guidance Clinician Kit during performance training and testing
- Recommendations for return to play
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