By Katherine De Tata, PT, DPT, and Justine Mamone-Lucciola, PT, DPT
Individuals who have survived a cerebrovascular accident (CVA) or an acquired brain injury (ABI) commonly present to an inpatient rehabilitation facility (IRF) with impairments that result in poor walking abilities. These impairments are addressed by a physical therapist who utilizes a variety of interventions to train proper walking mechanics and incrementally increase the timed intervals or measured distances of walking each therapy session. For those who are “not ready” to walk, the emphasis is traditionally placed on improving hemodynamic stability and upright tolerance first. Safe walking abilities, however, play a significant role in the determination of whether an individual discharges to home versus a skilled nursing facility.1 Upon admission to a facility such as Kessler Institute for Rehabilitation (KIR), headquartered in West Orange, NJ, there is often a limited length of stay that an individual is afforded to improve his/her walking ability and prepare for a return to home. Based on the severity of the injury, the typical length of stay across the country in an IRF is 9 days to 22 days.2 Hornby and colleagues indicated that substantial recovery in lower limb motor function, which is directly related to improved walking capacity, often occurs in the first 3 months following a stroke.1 With that being said, early and intense inpatient rehabilitation with a strong emphasis on walking is crucial within the time allotted.
Challenge of Gait Training
The overarching goal while in an IRF is for safe discharge to home with as little burden of care as possible and clinically, the most commonly reported goal of an individual receiving inpatient rehabilitation is to return to walking. Conventional therapeutic interventions used in an IRF are designed to address the vast number of impairments and functional limitations that may be present, yet with only 34% of time devoted to gait training.1,3 The remainder of the time spent within a therapy session is dedicated to lower extremity exercise (27%), balance (15%), and transfers (11%) with smaller percentages devoted to other areas, such as stair negotiation and upper extremity exercise.1 At KIR, physical therapists use conventional rehabilitation approaches including balance re-training, sensory integration, pre-gait activities, transfer training, gait and elevation training, and functional electrical stimulation as well as advanced technology that are incorporated into a plan of care. As for gait training, a variety of methods are used over ground as well as with the use of a treadmill.
One of the methods commonly used in gait training is incorporating a body weight support (BWS) system with the addition of manual facilitation, as needed, to minimize errors or compensatory strategies. Walking conditions are also varied by incorporating uneven surfaces, multi-directional stepping, obstacle negotiation, providing resistance, and dual tasking for a greater challenge. Often, the specificity, amount, and intensity of these interventions are inconsistent among clinicians during conventional plans of care. As the practice of physical therapy continues to evolve, there is more and more evidence becoming available that highlights the importance of incorporating high aerobic intensities into more consistent practice. Activities that provide an aerobic intensity ranging from 70%-85% of predicted maximum heart rate (HR) or heart rate reserve (HRR), as suggested by Hornby et al, is the target range to achieve during this type of intervention.1,4 It is, however, uncommon for individuals to achieve high aerobic intensities during conventional physical therapy sessions despite what their level of function may be.
Task Specificity and Intensity
High-intensity stepping training is defined as walking faster speeds or by increasing task demands with variability in practice.4 Adding greater intensity to conventional interventions by increasing repetitions of stepping practice and targeting high aerobic intensities will, in turn, increase neuromuscular and cardiovascular demands. Large amounts of task-specific practice are considered to be a critical variable to enhance plastic changes in the nervous system; thus, emphasizing the importance of incorporating this type of practice into rehabilitation for return to independent ambulation.1 Task specificity, in this case, would be specific to locomotor training (LT) since walking is the primary goal. Moore et al investigated changes in walking performance related to stepping dosage and demonstrated that the amount of practice performed during training may have contributed to the observed improvements in community ambulation.1,5 It has also been indicated that variability of task-specific practice rather than practice of variable tasks has been shown to modulate motor learning and ultimately contribute to improvements seen or desired.3
A variety of strategies are used to increase demand and task difficulty, including the addition of resistance bands, removing or reducing upper extremity support, adding additional weight to a limb or trunk via a cuff weight or weighted vest, increasing speed, stepping over obstacles, etc. The principle utilized by Moore and colleagues, specifically the FITT principle, is a training paradigm to help clinicians determine how to elicit increased stepping activity. FITT is defined as the frequency, intensity, time, and type of interventions. Creating FITT guidelines specific to each facility and therapeutic model assists in providing structure to the implementation of these interventions.1,5 The frequency and time are consistent with the treatment model used at KIR, as well as other IRFs across the country, making these interventions easy and effective to apply into practice.
Frequency and Focus
The frequency and time described by Moore et al was outlined to be two to five sessions per week for 4 weeks with a total treatment time of 45 minutes per session. The type of intervention utilized was LT over a treadmill with minimal body weight support and with varying degrees of physical assistance and/or facilitation. Walking speeds were varied to sustain intensity between 75% and 85% of predicted maximum HR. Many aspects of the FITT principle are currently utilized in conventional therapy except for consistently measuring HR, as well as a smaller emphasis on variability of stepping activities designed to specifically increase intensity. During the implementation of high-intensity stepping training, the focus switches from training normal gait kinematics to increasing training intensity and cardiovascular demands. Of note, when challenging locomotor tasks at high intensities and with a large amount of variability, errors in movement patterns may be present.1,5,6
Learning from Errors
Many conventional physical therapy models discourage errors, and therapists will traditionally intervene or correct errors during training in order to minimize compensation or poor mechanics. During high intensity LT the goal is for the individual to adjust his/her locomotor strategies or augment these errors in order to improve his/her performance without compensatory strategies. Holleran et al demonstrated that there are long-term improvements in walking performance with the implementation of error augmenting perturbations for specific gait deficits.6 In addition, there is a “reverse transfer effect” that shows early walking at higher intensities improves non-walking tasks. Often in conventional physical therapy, approximately 70% of a treatment session is spent practicing other therapeutic interventions including balance re-training, transfer training, and strengthening activities, and ultimately leaving little time for stepping practice.1 Knowledge of the “reverse transfer effect” allows the physical therapist to place the emphasis of treatment sessions on LT while their therapy counterparts can address other areas such as transfers.
As a physical therapist, it is largely important to be able to measure functional changes and express how these improvements relate to the patient’s social and employment roles for, not only reimbursement purposes, but also for patient buy-in. Outcome measures such as the 10 Meter Walk Test (MWT) and 2- or 6- Minute Walk Test are utilized to objectively measure walking speeds and distances, respectively.4,6 These outcome measures can provide insight into an individual’s ability to meet community demands, such as crossing a street or obstacle negotiation in the community. The 10 MWT and 2- or 6- Minute Walk Test in addition to other measures such as the Berg Balance Scale and the Five Times Sit-to-Stand Test have been used to identify and accurately track changes anticipated to occur.4 Research has shown that high-intensity stepping training has demonstrated improvements in the measures listed above, as well as improvements in lower extremity strength, power output via EMG, and transfer mechanics and levels of assist.1 Despite the outcomes that have shown improvements across multiple areas of recovery, like with many advanced interventions and technologies, there are still several barriers to implementation of high-intensity stepping interventions within practice.
The barriers to implementing high-intensity stepping training involve both the patient and the therapist. Gait training being the most-performed activity in an IRF, yet performed at much lower intensities with fears of potentially increasing spastic motor activity and/or abnormal movement patterns.3 For an individual functioning at a lower level, there are concerns regarding postural instability and safety with early stepping practice. Therefore, the focus defaults to static stability prior to initiating early stepping training. As previously mentioned, there is the potential of errors during high intensity LT that may pose concerns regarding safety, and with a lack of available resources, clinicians may not have the level of comfort required to independently implement these interventions. Despite the potential for errors or compensatory strategies with the various perturbations added during LT, upon removal of the perturbations, there should be immediate improvements in mobility.
In Pursuit of Continued Improvement
The goal continues to be to minimize compensatory strategies and to promote recovery and independence.4 If compensatory strategies are to arise over time, then these strategies are utilized to optimize independence outside of what the individual can achieve with his/her neural recovery capability. In this case, despite the presence of compensation, these individuals should still be pushed at higher intensities for the potential of continued improvements in overall mobility. The ongoing research that suggests the use of large amounts of high-intensity, task-specific locomotor training to improve walking performance and the suggested frequency, time, and type of intervention fits into the current treatment models utilized at KIR and other IRFs. However, for patients to receive the benefits of this type of practice, there needs to be a paradigm shift in the intensity of physical therapy interventions. In order to do this, continued training and education is required to provide clinicians with the knowledge of how to greater challenge their patients based on the parameters provided in the current literature. RM
Katherine De Tata, PT, DPT, is a Board-Certified Clinical Specialist in Neurologic Physical Therapy, Inpatient Brain Injury Unit, Kessler Institute for Rehabilitation, West Orange, NJ.
Justine Mamone-Lucciola, PT, DPT, is a Board-Certified Clinical Specialist in Neurologic Physical Therapy Inpatient Clinical Specialist Physical Therapist at Kessler Institute for Rehabilitation, Saddle Brook Campus. For more information, contact [email protected].
1. Horby TG, Straube DS, Kinnaird CR, et al. Importance of specificity, amount, and intensity of locomotor training to improve ambulatory function in patients poststroke. Top Stroke Rehabil. 2011;18(4):293-307.
2. Camicia M, Wang H, DiVita M, Mix J, Niewczyk P. Length of stay at inpatient rehabilitation facility and stroke patient outcomes. Rehabil Nurs. 2016; 41(2):78-90.
3. Horby TG, Moore JL, Lovell L, Roth EJ. Influence of skill and exercise training parameters on locomotor recovery during stroke rehabilitation. Trauma Rehabil. 2016;29(6):677-683.
4. Hornby TG, Holleran CL, Hennessy PW, et al. Variable intensive early walking Ppststroke (VIEWS): a randomized controlled trial. Neurorehabil Neural Repair. 2016;30(5):440-450.
5. Moore JL, Roth EJ, Killian C, Hornby TG. Locomotor training improves daily stepping activity and gait efficiency in individuals poststroke who have reached a “plateau” in recovery. Stroke. 2010;41:129-135.
6. Holleran CL, Straube DD, Kinnaird CR, Leddy AL, Hornby G. Feasibility and potential efficacy of high-intensity stepping training in variable contexts in subacute and chronic stroke. Neurorehabil Neural Repair. 2014;28(7):643-651.