For individuals with spinal cord injury (SCI), recovery of walking function is a primary patient goal and a common focus of physical therapy rehabilitation interventions.1,2 Rehabilitation lengths of stay for this population are decreasing.3 It is vital, therefore, for physical therapists to select the most effective intervention at the optimal time to maximize neurological recovery following SCI, and to have evidence-based methods to predict who will recover the ability to walk.
Many have developed clinical prediction rules (CPRs) or identified prognostic factors to help predict who will walk after SCI, using combinations of variables such as age, American Spinal Injury Association Impairment Scale (AIS) classification, and lower extremity motor and sensory scores. While these CPRs have facilitated clinical decision-making, recent evidence suggests that their applicability may be limited when applied to a single AIS severity classification.4 Additionally, household ambulation has been a commonly used outcome in CPRs, providing a narrow definition of walking recovery that may not align with patient expectations.
Jean and colleagues5 developed a CPR to predict long-term independent functional walking outcomes with walking defined as the ability to ambulate at least 100 m outdoors. In this issue of JNPT, Draganich and colleagues6 sought to validate the 2021 Canadian CPR using a multisite SCI dataset from the United States. This external validation study used a similar outcome: the ability to walk outdoors 1 city block, with or without a mobility aid. This study, however, allowed the use of bimanual assistive devices, whereas the original CPR did not. Clinicians should consider this (and the potential benefits of using a less restrictive assistive device) when evaluating CPR outcomes.
In addition to validating the accuracy, sensitivity, and specificity of the original CPR, this study determined an optimal CPR score threshold that predicted outdoor walkers versus nonwalkers. A cutoff score of greater than or equal to 33 was found predictive of outdoor walking.6 Having this access to an established cut score serves to reduce therapist burden and ambiguity in determining the significance of a score between 0 and 120, and is therefore of great value in the clinic.
Draganich et al cite that CPRs may be used to "drive clinical decision-making."6 CPRs can help physical therapists not only establish realistic and attainable goals and plan for long-term equipment needs, but also communicate prognosis and clinical rationale for therapeutic approaches with patients and their families. This may be especially beneficial for individuals whose prognosis may be favorable, but still guarded. For example, a patient who presents with no lower extremity motor function but intact S1 sensation can score a 60 using this CPR. This exceeds the Draganich cutoff score of 33, which is favorable for outdoor walking 1 year post-injury.6 While gait may not be an intuitive goal for someone lacking lower extremity function, this work by Draganich et al suggests that it is appropriate to focus on recovery-based interventions, and to consider future walking ability when making equipment recommendations. This could help therapists and patients make more appropriate, fiscally responsible decisions regarding mobility devices serving both short- and long-term needs.
The potential to regain walking function may influence patients' perspectives on their rehabilitation goals. Therapists have a responsibility to educate and guide patients so they can make the best decisions for themselves based on physical abilities, lifestyle, support system, and more. Therapists cannot ultimately make these decisions for their patients. For example, patients may be predicted to walk again, but should be educated that walking may look different than before, that bracing or assistive devices may be required, and that wheeled mobility may offer value given the speed, quality, or safety of locomotion.
The notion of walkers versus nonwalkers implies that gait function is dichotomous, when in fact, it may be viewed as a spectrum. We agree with Draganich et al's statement that "any degree of improved walking function (i.e. indoor surfaces and household) may be a top priority..."6 Even incremental improvements may have important daily utility for those with SCI. Walking into a bathroom where a wheelchair does not fit, for example, may drastically improve one's safety and independence, while decreasing caregiver burden, all of which can facilitate an improved quality of life. Gait training, therefore, should not be restricted to those with the potential for community ambulation alone based on a CPR. The patient's full presentation including lifestyle and personal goals must be considered.
It is important to consider potential limitations of this and other CPRs. First, the timing of the assessments used is relatively close to date of injury, an average of 13 days post-SCI in this article. Using assessments collected at a later date (>31 days post-injury) may impact the CPR's accuracy. Additionally, Draganich et al and others focus on walking ability 1 year post-injury. If CPRs could predict walking ability in the subacute time frame, or provide information on the trajectory of, or timeline for, walking recovery, they may prove more useful during decision-making in inpatient rehabilitation.7 Monitoring patients' progress using standardized outcome measures at regular intervals can help therapists refine plans of care throughout the inpatient stay.8 Finally, mechanism of injury or disease could be considered in future work, as current CPRs focus on individuals with traumatic SCI, and have been found less accurate in predicting who would walk after nontraumatic SCI.9
The validation of Jean and colleagues' CPR and the establishment of a cutoff score are important steps toward helping physical therapists more effectively serve this patient population. One CPR alone, however, cannot fully account for one's potential to regain walking function. Synthesizing the results of several CPRs with the physical therapist's clinical reasoning and additional patient factors (such as medical complexity, body composition, and psychosocial support) can improve clinicians' confidence in establishing functional prognosis. Draganich and colleagues have taken an important step in translating research to practice, and have added significant value to the rehabilitation field for both clinicians and patients.
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