Physical and Occupational Therapists play a critical role in managing neurodegenerative conditions like Parkinson’s disease (PD). However, a growing concern is underdosing — providing insufficient exercise intensity, duration, or frequency of exercise and physical or occupational therapy visits— leading to suboptimal outcomes.
The Risks of Underdosing
Underdosing occurs when therapists create a plan of care and include exercises that are too easy, lack progression, or fail to meet the necessary frequency or duration to achieve optimal outcomes. For older adults, this can exacerbate age-related muscle weaknees, deconditioning, balance issues, and reduced mobility. In PD, underdosing may insufficiently address motor symptoms like bradykinesia (slow movement) and hypokinesia (small movement), accelerating functional decline.
For patients with PD, underdosing undermines neuroplasticity—the brain’s ability to adapt through exercise. Research shows that intensive, goal-based training with sufficient repetition of practice is essential to counteract PDʼs motor impairments (Abbruzzese, et al., 2016, Nielsen, et al., 2015). Furthermore, the non-motor symptoms of PD including cognitive impairments, depression, apathy, anxiety, and sensory/kinesthetic awareness can make motor learning and performance more challenging (Olson, et al., 2019). Even greater repetition of practice may be needed to elicit robust and lasting outcomes as compared to treatment of musculoskeletal conditions.
A Personal Patient Story
I am reminded of a patient I had long ago, who I’ll call Ken. He taught me a lesson I will never forget. He had advanced PD and arrived at his physical therapy evaluation in a wheelchair pushed by his elderly wife. He appeared frail, and he spoke no more than ten words during the hour-long session.
Ken needed physical assistance with everything – transfers, bed mobility, dressing, toileting – literally everything. He could not walk more than a few steps with a walker and help. His wife of 60 years, Dorothy, was in poor health herself, and taking care of him was becoming harder.
Despite his frail appearance and lack of facial expression, both Ken and Dorothy wanted to try LSVT BIG®, on the recommendation of his neurologist. As a clinician who was newly certified in LSVT BIG, I was dubious that he could tolerate the intensity and frequency of LSVT BIG, and if he did, how much progress he would make. After completing his examination and educating them about this treatment option, which required sixteen one-hour sessions of PT over the course of a month, I could not find any reason to NOT give him a chance. And so, I did.
At that time, even though I was a seasoned therapist, I couldn’t have imagined what he would accomplish in just one month of intensive therapy. He gave me sixteen short hours of his life, and by the end, he was walking throughout his house with a walker and getting in and out of bed and chair with only supervision. The best part was that on his last session he was smiling, talkative, and gave Dorothy a gift that showed his love for her after all these years. They shared a short slow dance, and then he presented her with a letter in his “big” handwriting that he had been practicing all month. In the letter, he expressed his deep love and appreciation for her, especially in these last years as he struggled with PD. Needless to say, we were all in tears, and I was humbled.
This caused me to reflect on all the patients with PD I had seen before him. I typically would see them twice a week for a few weeks until I felt like they understood their home exercise program and had made some measure of improvement with their mobility, even if I was not confident that the changes would last. Had I failed them by setting my expectations too low and not pushing them adequately or seeing them often enough in physical therapy? Had I wasted their time and investment and caused them to think that “therapy did not work”? Suddenly I wanted to call them all up and “re-treat” them, but I had to accept that the only thing I could do was to never underestimate my patients’ potential again and never underdose their therapy again.
Why Does Underdosing Persist?
Common barriers to proper dosing include:
- Not knowing what the optimal dosage of therapy is. While there are evidence-based guidelines for exercise in PD, beyond standardized therapy protocols like LSVT BIG, there is little consensus in published literature about the optimal dosage of physical and occupational therapies for PD (Osborne, et al., 2022; El Hayek, et al., 2023). This leaves it up to the clinical judgment of individual therapists, who may vary widely in their practice patterns related to dosing. There is freedom in this, but with this freedom comes a risk of underdosing and a lack of certainty or confidence about expected outcomes, despite a sizeable investment in time from both the therapist and patient.
- Misconceptions about patient capacity: Therapists may underestimate patients’ ability to tolerate high-effort exercise and frequent therapy visits when they are elderly and/or have advanced PD. They can be reactive instead of proactive when patients have fatigue, appear frail, lack facial expression, and may be deconditioned.
- Scheduling constraints: Patients sometimes experience logistical challenges (e.g., transportation, insurance) which therapists are unsure of how to overcome through solutions like telehealth, mobile practice, patient education, etc. Other times, therapists have to “ration” care when there are too many patients to squeeze in their schedule, or they work for a system that has a “one size fits all” scheduling system leaving no room for therapist autonomy.
- Lack of specialization: Not all therapists are trained in PD-specific treatment protocols like LSVT BIG, leading to generic plans of care that include “sprinkles” of different forms of exercise recommended by clinical practice guidelines, but not delivered even close to the dosage that was found to be efficacious for that type of exercise according to the literature.
- Bias: No one likes to admit they are biased, but we all have experienced this if we are being honest. We may be biased about different types of treatment interventions, and we may be biased about what we think is best for patients based on their age, diagnosis, co-morbidities, gender, social situation or a hundred other things.
LSVT BIG: A Solution to Underdosing
LSVT BIG, an exercise-based physical and occupational therapy protocol designed to increase movement amplitude, exemplifies this principle. Over 40 published studies on LSVT BIG have validated the effectiveness when delivered at the prescribed dosage of 16 hours of therapy (1-hour sessions, 4 days/week for 4 weeks) to recalibrate sensory feedback and retrain motor patterns. Deviating from this dosage risks diminishing its effectiveness as demonstrated in two studies, one where LSVT BIG was delivered five times a week for two weeks, and another where LSVT BIG was delivered twice a week (Ebersbach, et al., 2015; Eldemir, et al., 2024).
LSVT BIG addresses underdosing by enforcing a standardized, high-intensity exercise regimen:
- Amplitude training: Patients perform dynamic exercises targeting large movements throughout the whole body and then apply these bigger movements to personalized functional skills, such as transfers, walking, dressing, cooking a meal, etc. This focus on amplitude counteracts the tendency toward small, slower movements that are common in PD.
- Intensity and repetition of practice: The exercises are performed intensively with high effort to also capitalize on the physiological benefits of aerobic exercise. Patients are seen for 60-minute sessions, a minimum of four days a week for four weeks. Over the course of this month of therapy, they will literally perform three to five-thousand repetition of “big” movements.
- Sensory recalibration: Therapists help patients recognize and correct their internal perception of movement size, which is often distorted in PD.
- Daily homework: Patients practice exercises and functional skills for 15-20 minutes daily to reinforce new motor patterns outside of therapy.
Studies confirm the efficacy of LSVT BIG in improving motor function, balance, and quality of life when delivered at the prescribed dosage. For example, telerehabilitation trials show comparable outcomes to in-person sessions, expanding accessibility without compromising intensity (Ekmekyapar Fırat, et al., 2023; Kaya Aytutuldu, et al., 2024).
Moving Forward into the Future
To combat underusing, therapists must prioritize evidence-based approaches and collaborate with patinets and therapy managers to overtime barriers. For PD, the validated dosage of LSVT BIG serves as a model for delivering targeted, effective care.
Without becoming certified in LSVT BIG, would I have ever scheduled my outpatients with PD four or more times a week? Most likely not, but thankfully I did and learned how much frequency, intensity and repetition of practice matter and make a huge difference in size and duration of outcomes. My bias was crushed!
By utilizing such frameworks, clinicians can ensure older adults and PD patients receive the exercise intensity needed to achieve their highest potential, maintain independence and slow disease symptom progression.
To learn more about LSVT BIG treatment for Parkinson’s and other neurological disorders or to find a certified clinician in your area, visit https://www.lsvtglobal.com/
Explore online and live LSVT BIG Training and Certification Courses for Physical Therapy and Occupational Therapy professionals and students at https://lsvtstore.mybigcommerce.com/.
References
Abbruzzese, G., Marchese, R., Avanzino, L., & Pelosin, E. (2016). Rehabilitation for Parkinson’s disease: Current outlook and future challenges. Parkinsonism & related disorders, 22 Suppl 1, S60–S64. https://doi.org/10.1016/j.parkreldis.2015.09.005
Jens Bo Nielsen, Maria Willerslev-Olsen, Lasse Christiansen, Jesper Lundbye-Jensen & Jakob Lorentzen (2015) Science-Based Neurorehabilitation: Recommendations for Neurorehabilitation From Basic Science, Journal of Motor Behavior, 47:1, 7-17, DOI: 10.1080/00222895.2014.931273
Olson, M., Lockhart, T. E., & Lieberman, A. (2019). Motor Learning Deficits in Parkinson’s Disease (PD) and Their Effect on Training Response in Gait and Balance: A Narrative Review. Frontiers in neurology, 10, 62. https://doi.org/10.3389/fneur.2019.00062
Osborne, J. A., Botkin, R., Colon-Semenza, C., DeAngelis, T. R., Gallardo, O. G., Kosakowski, H., Martello, J., Pradhan, S., Rafferty, M., Readinger, J. L., Whitt, A. L., & Ellis, T. D. (2022). Physical Therapist Management of Parkinson Disease: A Clinical Practice Guideline From the American Physical Therapy Association. Physical therapy, 102(4), pzab302. https://doi.org/10.1093/ptj/pzab302
El Hayek, M., Lobo Jofili Lopes, J. L. M., LeLaurin, J. H., Gregory, M. E., Abi Nehme, A. M., McCall-Junkin, P., Au, K. L. K., Okun, M. S., & Salloum, R. G. (2023). Type, Timing, Frequency, and Durability of Outcome of Physical Therapy for Parkinson Disease: A Systematic Review and Meta-Analysis. JAMA network open, 6(7), e2324860. https://doi.org/10.1001/jamanetworkopen.2023.24860
Ebersbach, G., Grust, U., Ebersbach, A., Wegner, B., Gandor, F., & Kuhn, A. A. (2015). Amplitude-oriented exercise in Parkinson’s disease: A randomized study comparing LSVT-BIG and a short training protocol. Journal of Neural Transmission, 122(2), 253-256. https://doi.org/10.1007/s00702-014-1245-8
Eldemir, S., Eldemir, K., Saygili, F., Ozkul, C., Yilmaz, R., Akbostancı, M. C., & Guclu-Gunduz, A. (2024). The effects of standard and modified LSVT BIG therapy protocols on balance and gait in Parkinson’s disease: A randomized controlled trial. Brain and behavior, 14(3), e3458. https://doi.org/10.1002/brb3.3458
Ekmekyapar Fırat, Y., Turgay, T., Soğan, S. S., & Günel Karadeniz, P. (2023). Effects of LSVT-BIG via telerehabilitation on non-motor and motor symptoms and quality of life in Parkinson’s disease. Acta neurologica Belgica, 123(1), 207–214. https://doi.org/10.1007/s13760-022-02104-x
Kaya Aytutuldu, G., Ersoz Huseyinsinoglu, B., Karagoz Sakalli, N., Sen, A., & Yeldan, I. (2024). LSVT® BIG versus progressive structured mobility training through synchronous telerehabilitation in Parkinson’s disease: A randomized controlled trial. Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology, 45(7), 3163–3172. https://doi.org/10.1007/s10072-024-07322-0
