“You want me to do what?” says Susan when she hears the drill that I want her to complete during our exercise class. 

“You’ve gotta be kidding me! Where do you come up with these drills? You DO remember I have Parkinson’s Disease?” To which I smile and reply, “Yes, and you can do this, I promise!!” 

Susan rolls her eyes and jokingly replies, “Right, I guess we’ll just have to see about that, Colleen!”

“You can do this Susan,” I reply, “but it is going to require work, and I’ll be right here to help you.”

You may be thinking to yourself, what kind of drill is Colleen asking her client to perform? Could it be a 150lb deadlift? Maybe it’s a 5ft plyo-jump on one leg or possibly a 3 minute plank? Not even close! While the deadlift, jump and plank are all fantastic exercises, I’m asking Susan to do a lunge series with lateral arm lift series which incorporates Bilateral Coordination.

Bearfoot OT and Noémie von Kaenel, OTS share that bilateral coordination is the integration and sequencing of movement by using “two parts of the body together for motor activities”.

“To coordinate two-sided or bilateral movements, the brain needs to communicate between both its hemispheres through the corpus callosum which we will discuss later on. But it is important to note that this area of the brain develops at 20 weeks but connections between the two hemispheres strengthen and develop as a child develops . Bilateral coordination is also closely linked to the vestibular system (where your head is in space), posture, and balanced movements.”

For example: We all grew up challenging our friends to pat their head and rub their tummy at the same time. Then switch hand placement and repeat. Take a second and give it a try! Did you find one hand placement easier than the other? Now, imagine that you have Parkinson’s Disease (PD) and you’ve been given this challenge. You would probably tell me that it was tough on both sides. Why is that? 

Let’s take a few moments and discuss Parkinson’s Disease so you understand the challenge of Bilateral Coordination.

By definition, Parkinson’s Disease is a neurodegenerative disorder that affects predominantly dopamine-producing neurons in the Substantia Nigra (SN) (Latin for “Black Substance”, due to its darkened pigment in the brain). The substantia nigra contains the highest concentration of dopamine neurons. It is a part of the Basal Ganglia, an area responsible for motor control, motor learning, and procedural memory, such as learning how to tie your shoes. 

Substantia Nigra in Normal Brain vs. Parkinson’

Without the Substantia Nigra, the brain and body simply do not communicate as well, or at all depending on the stage of PD. To us, fitness professionals, we observe those living with Parkinson’s Disease displaying uncoordinated movements, loss of balance, poor gait, postural issues, visual tracking problems, rigidity, tremor, freezing, facial masking, inability to focus on a task or process information clearly, bradykinesia, hypophonia (volume of voice)… and as it pertains to Bilateral Coordination, the challenge to perform a drill with one side of the body such as the left arm while moving the right leg.  Now your wheels are turning and you are probably asking yourself…

Why Is Bilateral Coordination Important?  

Bilateral Coordination requires your small and large motor and visual-motor functioning to work together making it possible to accomplish ALL of your daily tasks! For example, in order to write your grocery list on a piece of paper, you need to hold the paper with one hand while writing the note at the same time. 

Proprioception or body awareness is another great reason to work on Bilateral Coordination. Throughout our entire life, we have the ability to know where our body is in time and space. For the person living with Parkinson’s Disease, this means a lower risk of falling, and believe me, that is crucial!

What Is The Scientific Explanation Of Bilateral Coordination?   

We learned in a previous article, “How a Thought Becomes an Action”, that motion in the brain is complicated and there are numerous steps to ensure that the motion in the brain is coordinated and precise. This all starts in the motor cortex, goes through the spine into motor neurons and muscles, and goes back into the brain to be fine-tuned by the basal ganglia (keep in mind this is where the substantia nigra resides). But now we’re adding onto this process by adding on even more coordinated movement in:

• The premotor cortex
• Supplementary motor area
• The cerebellum
• And the corpus callosum

Each one of these areas works in tandem with the movement pathways we discussed previously to produce bilateral movement and is the reason that I can type and you can read this paper right now. Let’s go over what each of these areas does, starting with the premotor cortex (Figure 1, below).

Fig. 1 The neural pathway from stimulus sensation to movement response.

• The premotor cortex is more involved in the planning of movement rather than the execution is important for bilateral coordination in movements even as simple as walking. 
  • When walking, the premotor cortex would be important for planning the gait length required to keep our balance, the speed, and overall how the movement is going to go so we don’t crumple or trip over our own feet (to some extent anyway…)
• The supplementary motor area (SMA) is also involved in planning movement, but in a different way. 
  • The SMA is planning for movements both ipsilaterally (scientific jargon for same-side), and contralaterally (scientific jargon for different-side).
    • While the premotor cortex is planning for what muscles have to move to do the actual action, the SMA is controlling which sides are going to go first to maintain balance and what makes the most sense given the environment we would be walking in.
• The cerebellum is less involved in conscious movement but is extremely involved in coordination and balance, which is needed for performing tasks bilaterally. 
  • When walking, we need our brain to fine-tune the balancing and counterbalancing errors (such as arm swing), which happens in the cerebellum. Think of the cerebellum like an editor. The movement keeps happening, and each time it keeps getting better and easier because of the error calculations the cerebellum makes.
• The corpus callosum, which works in tandem with the rest of the cortex to send signals to the different halves of the brain. 
  • What happens on one side doesn’t always translate to the other side, which is where the corpus callosum comes in. Each side has its own control mechanisms for the opposite side of the body (talk about contralateral). The corpus callosum is the phone line that connects these two hemispheres so they can talk to each other and get the messages for both sides of the body into a beautifully coordinated orchestra of neuronal firing and muscle movements.

So given these four areas of the brain, along with the rest of the movement pathway, there are numerous elements here contributing to sensory integration, planning of movement, checkpoints for these movement executions, and a miscommunication playing out on both sides of the brain. This means that there are a lot of alternate pathways in case anything goes wrong. However, pathways can deteriorate over time, and problems can arise. Which brings us to PD, and the issues that may happen in bilateral coordination as the disease progresses.

How Does Bilateral Coordination falter in the PD brain?

There’s a lot of different attributes to movements like walking –  a complicated movement with a number of variables:

• First, you have to start walking.
  • Because it requires a lot of input all at once, it’s hard for the brain to do subconsciously, especially for someone who has PD. similar to revving a car for the first time after stopping at a red light.
• Then you have sensory cues.
  • These can be challenges like incline or decline, which determines how much effort you need to stay upright, stay up to speed, and how much force you need to put into your step to keep up with gravity (like a driver constantly paying attention to the road).
• Once you start walking, your brain can put less effort into what researchers call “steady-state walking”, where your legs follow the same instructions repeatedly, similar to coasting on a highway (2).
• Next, we get to turning, where walking requires more input such as:
  • Balancing on one leg while pivoting the other
  • Slowing down, and speeding back up again (all while navigating those sensory cues, mind you), which is where a lot of the times this bilateral coordination seems to freeze up in PD, hence the clinical symptom called freezing of gait (FOG).
  • Thinking again of the car analogy, this is akin to having to slow down and turn the wheel the proper amount so you don’t hit the curb but you make it to the proper lane, speeding back up again.

With all those steps, anything that goes wrong will hurt the body’s ability to keep steady and coordinate larger and smaller movements on both sides. We also need to take into consideration that we all have a dominant side in normal movement that is easier to control. Evidence suggests the dominant side is worse in PD, perhaps due to brain asymmetry, meaning anything involving that side is most likely going to be slower and more uncoordinated, such as balancing on your dominant side or having to pivot on your dominant foot (1,2). Again, comparing it to a car running, if you have a bad steering wheel, your turns are going to be a little rough and you might end up swerving more or less on target. Or you need new adjustments or wheel bearings that make your balance and steadiness just a little bit better (speaking from personal experience). These parts make a car drive smoothly, as the neural circuits involved in the basal ganglia — along with all the new motor regions I mentioned–interact as one unit to make the walking as coordinated as possible.

This type of movement is also affected by our favorite neurotransmitter: dopamine. As we know, dopamine affects the basal ganglia, which has a conversation with all of the different areas we’ve talked about, such as the supplementary motor area, which is important for coordinating movements. We have seen in past research that taking dopaminergic medication has positively affected Phase Coordination Index (PCI), which measures bilateral coordination by looking at footsteps and foot switching (4). What does this mean exactly? Taking dopaminergic medications creates a more balanced movement, most likely by increasing basal ganglia activity, which thus increases the conversation between this and other movement areas needed for bilateral movement.

We also know that exercise is great for PD! Not only has this been seen in PD-specific fitness classes, but in research as well! Taking medications that increase dopamine uptake can mitigate some of these falters in movement and can create a more efficient signaling cascade, but it can only do so much. The other part of strengthening these pathways comes from exercise that can lead to better balance, smoother motion, and greater bilateral coordination! We’ve seen in some research studies on physical therapy techniques that auditory and visual cues, premeditated/thoughtful movements, and most importantly repeated balance drills can decrease FOG episodes, which could be attributed to a lack of bilateral coordination (3).

And what incorporates all of those? Exercise classes! In Part 2, we discuss Steps To Incorporating Bilateral Coordination Into Your Exercise Program.

Become a Parkinson’s Disease Fitness Specialist!

Check out Colleen’s online course on MedFit Classroom….

Co-Written by Colleen Bridges, M.Ed, NSCA-CPT and Renee Rouleau.

Colleen Bridges is the author of MedFit Classroom’s Parkinson’s Disease Fitness Specialist course. Renee Rouleau is a PhD student at the Jacobs School of Biomedical Sciences, University at Buffalo.

References

1. van der Hoorn, A., Bartels, A. L., Leenders, K. L., & de Jong, B. M. (2011). Handedness and dominant side of symptoms in Parkinson’s disease. Parkinsonism & Related Disorders, 17(1), 58-60. https://doi.org/https://doi.org/10.1016/j.parkreldis.2010.10.002
2. Plotnik, M., & Hausdorff, J. M.. (2008). The role of gait rhythmicity and bilateral coordination of stepping in the pathophysiology of freezing of gait in Parkinson’s disease. Movement Disorders, 23(S2), S444–S450. https://doi.org/10.1002/mds.21984
3. Rutz, D. G., & Benninger, D. H.. (2020). Physical Therapy for Freezing of Gait and Gait Impairments in Parkinson Disease: A Systematic Review. PM&R, 12(11), 1140–1156. https://doi.org/10.1002/pmrj.12337
4. Son, M., Han, S. H., Lyoo, C. H., Lim, J. A., Jeon, J., Hong, K.-B., & Park, H.. (2021). The effect of levodopa on bilateral coordination and gait asymmetry in Parkinson’s disease using inertial sensor. Npj Parkinson’s Disease, 7(1). https://doi.org/10.1038/s41531-021-00186-7
5. Kramer P., & Hinojosa, J., (2010). Frames of Reference for Pediatric Occupational Therapy: 3rd Edition. Baltimore, Maryland: Lippincott Williams & Wilkins
6. Magalhães, L.C., Koomar, J.A., Cermal, S.A. (1989, July) Bilateral Motor Coordination in 5- to 9-year old children: a pilot study. The American Journal of Occupational Therapy. Volume 43 Number 7.
7. Piek, J.P., Dyck, M.J., Nieman, A., Anderson, M., Hay, D., Smith, L.M., McCoy, M., Hallmayer, J., (2003) The relationship between motor coordination, executive functioning and attention in school-aged children. Archives of clinical neuropsychology. Elsevier’s Ltd. doi:10.1016/j.acn.2003.12.007
8. Roeber, B.J., Gunnar, M.R. and Pollak, S.D. (2014), Early deprivation impairs the development of balance and bilateral coordination. Dev Psychobiol, 56: 1110-1118. https://doi.org/10.1002/dev.21159
9. Rutkowska, I., Lieberman, L. J., Bednarczuk, G., Molik, B., Kaźmierska-Kowalewska, K., Marszałek, J., & Gómez-Ruano, M.-Á. (2016). Bilateral Coordination of Children who are Blind. Perceptual and Motor Skills, 122(2), 595–609. https://doi.org/10.1177/0031512516636527
10. Schmidt, M., Egger, F., & Conzelmann, A. (2015). Delayed Positive Effects of an Acute Bout of Coordinative Exercise on Children’s Attention. Perceptual and Motor Skills, 121(2), 431–446. https://doi.org/10.2466/22.06.PMS.121c22x1
11. Tseng, Y., & Scholz, J. P. (2005). Unilateral vs. bilateral coordination of circle-drawing tasks. Acta Psychologica, 120(2), 172-198.

In Part 1, we discussed how a thought becomes an action, and the disconnect in Parkinson’s Disease, as well as how a Fitness Professional do to improve brain and body connection.

For those living with Parkinson’s, the three Activities of Daily Living (ADLs) considered to be most difficult to perform are:

• Rolling over in bed
• Getting out of a vehicle
• Working through a freeze episode while crossing over a threshold between rooms.

I have provided a list of exercises to complement these ADLs as well as a “Practice Option” that combines the exercises listed.

Considerations

1. Remember to begin with the most basic of movements until the client can properly and safely execute the exercise.
2. Care partners of wheelchair-bound clients need to be instructed on how to safely assist loved ones without causing injury to either person. Please refer the client to an Occupational Therapist if needed.

Activity of Daily Living: Rolling over in bed                                         

Exercises

• Bridges
• Push-ups or chest press
• Tricep extension
• Rows
• Glute squeezes (for chair bound)
• Lateral Step with torso rotation using a tube
• Side Planks/ Prone Plank
• Clamshells

Advanced Practice Option: Have the client lay on his or her back. Take the right leg and swing the leg over the left leg and move into the side plank position and hold for 5 counts. From there roll to a prone plane OR bird dog position. Reverse the exercise to practice returning to the supine position.

Assisted Practice Option: If lying down is not an option, have the client sit in a chair.  Have the client hold a tube with both hands in front of them. Trainer provides tension from the side and the client maintains the isometric hold while picking up one leg and moving it out to the side and bringing it back in like a seated jumping jack.

Activity of Daily Living: Getting in/out of vehicle

Exercises

• Rows (add a diagonal step/lunge)
• Squats/Lunges
• Sit to Stand drill (include single leg version)
• Bridges
• Clamshells (or any abduction work)
• ½ Warrior step / ½ Gong arms
• “Step over the Fence” ( lift left knee and step laterally over the “fence” followed by the right knee and then reverse the movement)
• “Jazz Hands” (improves ability to reach)
• Hip circles
• Bob-n-weave (or lean left/right if needed)
• Side planks or oblique bend
• Tricep/Biceps (add lower body exercise)

Advanced Practice Option: (Stand with chair next to left leg). Place a hurdle next to chair to act as the “floorboard” of the car. Client will stand alongside the “car”.  Client will then lift the left knee and hold for 3-5 counts then step “over the fence”/bob-n-weave” to get into the car. Reverse the motion to practice getting out of the car. Repeat on the other side.

Assisted Practice Option: (Begin in a chair and with a short hurdle or object for them to “step” over). Client is in the chair and reaches right arm out as if opening the car door (jazz hands). Client then comes back to center and picks up the right knee and steps over the hurdle and turns foot to the right (½ warrior/ ½ gong) as the entire body turns to the right. Left foot follows the right foot and steps over the hurdle. Once the feet are facing the right, have the client do a full or partial Sit-to Stand drill. Reverse the motion to practice getting into the car.

Activity of Daily Living: Working through a “freeze” episode 

Exercises

• Obstacle courses
• Stop and start gait drills
  • Walk and turn head right and left
  • Walk slow then fast then slow etc
  • Walk and at cue, stop and turn
• Visual drills
• Lateral steps 5x then walk forward
• Walk to a song with a strong beat
• Criss-Cross Applesauce

*If client freezes at room threshold, emphasize that they want to look straight ahead and not down.

These three ADLs are just a few of the frustrating tasks people living with Parkinson’s Disease deal with each and every day.  Fitness Professionals can make a real difference in someone’s life if they will take the time to consider how movement works, where it can go wrong, and what to do to help it go right again. Imagine the success your client will experience during a session and throughout the day as they tackle ADLs with minimal effort! I can tell you this, their level of confidence will soar and the future will be something they look forward to.

Work with Parkinson’s Clients and Change Lives!

Working with Parkinson’s clients is an extremely rewarding experience. Check out Colleen’s course, Parkinson’s Disease Fitness Specialist to get started.

Colleen Bridges has worked for nearly 17 years as an NSCA Certified personal trainer, group exercise instructor and fitness consultant and as an independent contractor for Nashville’s first personal training center, STEPS Fitness. Her passion for understanding the body in sickness and in health, and how it moves, as fed her interest in and enhanced her talent for working with senior adults, especially those living with a neurological disorder such as Parkinson’s Disease.

Renee Rouleau is a Clinical Research Coordinator for the Department of Neurology at Vanderbilt Movement Disorder. Her research primarily focuses on the glymphatic system, a proposed waste-clearance system in the central nervous system in different neurodegenerative disorders such as Parkinson’s Disease (PD) and Alzheimer’s Disease (AD).

It’s 2am and Robert needs to use the restroom but can’t gather enough strength to roll to a seated position to get out of bed without his wife’s help.

Gus decides to go to the kitchen for a snack but “freezes” when he reaches the doorway. His feet feel like they are stuck in mud.

Mary would like to attend her exercise class but the process of getting in and out of the car leaves her exhausted.

What do all of these people have in common? They have a progressive neurological disease called Parkinson’s Disease (PD). Parkinson’s Disease affects the dopamine-producing neurons in the substantia nigra (Latin for “Black Substance”, due to its darkened pigment in the brain).  The substantia nigra contains the highest concentration of dopamine neurons.  It is a part of the Basal Ganglia, an area that is responsible for motor control, motor learning, and procedural memory such as learning how to tie your shoes.

In PD, the onset of dopaminergic neuronal death in the substantia nigra manifests itself in the form of motor and non-motor symptoms that occur over a long period of time and in a progressive fashion.  Most people are not aware they are presenting symptoms of PD until a loved one brings their attention to a tremor, lack of arm swing, or notices a series of falls.

People living with Parkinson’s Disease want to take larger steps, smile more, swallow food without fear of choking, dress and bathe themselves, drive and participate in social activities.

However, for some, when they have a thought such as “I want to walk to the kitchen for a snack”, getting the thought to become an action, is almost impossible due to the lack of dopamine neurons in the Substantia Nigra. But wait a minute! HOW does a thought even become an action and WHAT can a Fitness Professional do to improve brain and body connection?

How a thought becomes an action

The brain is constantly multitasking as it takes in stimuli from your surroundings, interprets what’s going on around you and causes you to take action.  When your mind creates a conscious thought, such as “I want to get a snack”, a chain reaction takes place in the brain involving several areas. This starts in the frontal areas of your brain after processing the stimuli leading to the thought. For example, if you have your eyes set on the kitchen to get a snack, your prefrontal cortex initiates plans to make the movement, sending signals to your premotor cortex to organize those plans, and then sends those signals to the motor cortex to carry out the movement.

Once the movement has been planned and the best course of action has been “decided” by these neurons, the movement can commence. This creates the surge of neuronal firing from the motor cortex through the spinal cord to motor neurons that communicate with muscles and finally manifests the movement.

The above seems straightforward. The tricky part is regulating all of those different areas. Once the gross movement is executed, sensory information ( i.e. touch, temperature, or force) travels back up to the brain through sensory neurons in the spinal cord. The sensory cortex receives and carries the message to other parts of the brain that fine-tune the movement. This is one of the functions of the basal ganglia and other areas in the midbrain.

Because you’ve most likely done these types of movements before, those patterns are all stored in the basal ganglia so it doesn’t take up valuable space in the motor cortex. This area talks back and forth to the frontal areas to figure out what specific pattern should be used to achieve the best result. There are a hundred different ways to get out of a chair and go to the kitchen, but the basal ganglia works together to choose the most efficient option out of all of them and keeps the movements from getting out of control so you’re not high knee-ing to the kitchen when a simple walk will do (unless you want to high-knee to the kitchen). Once everything is adjusted and looks correct, new sensory information goes to the sensory cortex and back to those frontal areas to then signal that the movement has been fully executed.

Now, although that looked like a lot of steps just to complete one movement, this all happens within a fraction of a second, and is constantly going as you move to correct and adjust. The process is fluid, but works as a chain. If one link is broken, the rest of the process is going to fall apart. So how is the link broken in a disease like Parkinson’s?

Because the basal ganglia gets a lot of communication from the substantia nigra, if there is a loss of any sort of dopamine neurons, the relay of information gets discombobulated and, in the case of Parkinson’s, causes the motor system to stop the movement mid-way as there is not enough information from the neurons firing. Instead of creating the controlled movements and fine motor adjustments like you would see in a regular motor response, you have freeze-ups where the frontal areas are telling the midbrain to do one thing, and the basal ganglia just can’t do what it’s being told to do. Thus, the chain of movement is broken and the body cannot execute the action properly. To most, it looks like people with PD can’t seem to execute an action because of cognitive reasons. However, from their perspective, they want to be able to execute it and are consciously telling themselves to do it, but part of their brain isn’t “listening” and it causes the brain and body to be disconnected, resulting in incomplete movements and motor symptoms such as resting tremor, freezing of gait, and rigidity. This is why when PD patients take their medications, which help the brain to produce dopamine, they have “on” periods where these areas are able to have clearer communication with each other, their movements are better and their symptoms are better managed.

This is critical information for Fitness Professionals working with people living with Parkinson’s Disease. Once the information is understood, Fitness Professionals can focus on the second question which is “What can a Fitness Professional do to improve the brain-body connection for those living with Parkinson’s Disease?”

First, remind them that Exercise is Medicine! They need to take a dose each and every day! And the good news is that exercise provides outcomes such as:

• Improved neuro-protection for at-risk dopamine neurons
• Neuro-repair for areas of the brain affected by Parkinson’s Disease, and
• Adaptation by retraining areas of the brain to pick up where the damaged parts can no longer execute commands.

Second, determine the activities of daily living (ADLs) that are most difficult for them. Identifying the ADLs and providing an exercise program that includes the seven functional movement patterns (push, pull, carry, hinge, lunge, squat and rotation) to improve their ability may save their lives. Repetition will be the key to create a spirit of confidence!

In Part 2, I discuss the three ADLs considered by most people living with Parkinson’s Disease to be most difficult, and exercises to complement them.

Colleen Bridges has worked for nearly 17 years as an NSCA Certified personal trainer, group exercise instructor and fitness consultant and as an independent contractor for Nashville’s first personal training center, STEPS Fitness. Her passion for understanding the body in sickness and in health, and how it moves, as fed her interest in and enhanced her talent for working with senior adults, especially those living with a neurological disorder such as Parkinson’s Disease.

Renee Rouleau is a Clinical Research Coordinator for the Department of Neurology at Vanderbilt Movement Disorder. Her research primarily focuses on the glymphatic system, a proposed waste-clearance system in the central nervous system in different neurodegenerative disorders such as Parkinson’s Disease (PD) and Alzheimer’s Disease (AD).