Chad Swank Ph.D.

Almutairi, S. M., C. Swank, S. S. Wang-Price, F. Gao and A. Medley (2021). “Walking with and without a robotic exoskeleton in people with incomplete spinal cord injury compared to a typical gait pattern.” NeuroRehabilitation. [Epub ahead of print].

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BACKGROUND: Robotic exoskeleton (RE) enables individuals with lower extremity weakness or paralysis to stand and walk in a stereotypical pattern. OBJECTIVE: Examine whether people with chronic incomplete spinal cord injury (SCI) demonstrate a more typical gait pattern when walking overground in a RE than when walking without. METHODS: Motion analysis system synchronized with a surface electromyographic (EMG) was used to obtain temporospatial gait parameters, lower extremity kinematics, and muscle activity in ambulatory individuals with SCI and healthy adults. RESULTS: Temporospatial parameters and kinematics for participants with SCI (n = 12; age 41.4±12.5 years) with and without RE were significantly different than a typical gait (healthy adults: n = 15; age 26.2±8.3 years). EMG amplitudes during the stance phase of a typical gait were similar to those with SCI with and without RE, except the right rectus femoris (p = 0.005) and left gluteus medius (p = 0.014) when participants with SCI walked with RE. EMG amplitudes of participants with SCI during the swing phase were significantly greater compared to those of a typical gait, except for left medial hamstring with (p = 0.025) and without (p = 0.196) RE. CONCLUSIONS: First-time walking in a RE does not appear to produce a typical gait pattern in people with incomplete SCI.

Shearin, S., Medley, A., Trudelle-Jackson, E., Swank, C. and Querry, R. (2021). “Differences in predictors for gait speed and gait endurance in Parkinson’s disease.” Gait Posture 87: 49-53.

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INTRODUCTION: Both gait speed and gait endurance directly impact independence and community engagement for individuals with Parkinson’s disease (PD). However, factors accounting for variability in gait speed and gait endurance performance are unclear. The purpose of this study was to investigate whether key factors associated with gait speed in individuals with PD also predicted gait endurance. METHODS: Community dwelling ambulatory individuals with PD were recruited for a single session. Key measures included 10 Meter Walk Test (10MWT) and 6 Minute Walk Test (6MWT) and key factors: age, disease severity [Movement Disorders Society United Parkinson’s Disease Rating Scale (motor scale only) (MDS-UPDRS motor)], plantar flexor strength [Calf Raise Senior (CRS)], fatigue [Fatigue Severity Scale (FSS)], cognition [Montreal Cognitive Assessment (MoCA)], and balance [Four Square Step Test (FSST)]. Multiple linear regression analyses were conducted to determine clinical relationships. RESULTS: Seventy-two individuals with PD (mean (standard deviation) (age = 70.83 (7.91) years; 50 males; MDS-UPDRS motor = 30.67 (13.50)) completed all assessments. The model predicting gait speed was significant, F(6, 65) = 15.143, p <.001, accounting for 54 % of the variance. Of the predictor variables age, MDS-UPDRS motor, CRS, MoCA and FSST scores were significant predictors. The model predicting gait endurance was significant, F(6, 65) = 15.608, p <.001, accounting for 55 % of the variance. Of the predictor variables, age, MDS-UPDRS motor scale, and CRS scores were significant predictors. DISCUSSION: Gait speed and gait endurance are similarly influenced by age, motor impairment, and plantarflexion strength. However, cognition and balance were predictors only of gait speed, which may suggest unique task differences exist between gait speed and gait endurance.

Shearin, S.M., Medley, A., Trudelle-Jackson, E., Swank, C. and Querry, R. (2021). “Plantarflexor strength, gait speed, and step length change in individuals with Parkinson’s disease.” Int J Rehabil Res 44(1): 82-87.

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Parkinson’s disease affects the ability to walk often resulting in decreased independence and low quality of life. The purpose of this study was to examine differences in plantarflexor strength (PFS), gait speed, and step length in persons with Parkinson’s disease (PwP) and healthy peers using clinical measures. A secondary purpose was to examine the relationship between these gait components across disease severity. The study was a convenience sample of 71 PwP and 25 community healthy peers. Outcome measures included 10-Meter Walk, step length, and Calf-Raise Senior Test. PwP were separated into mild and moderate impairment groups using the Movement Disorders Society United Parkinson’s Disease Rating Scale Motor Subscale. Between group differences for gait speed (F2,93 = 24.560, P = 0.000), step length (F2,93 = 21.93, P = 0.000) and PFS (F2,93 = 19.49, P < 0.000) were observed. Post hoc testing determined a difference (P < 0.00) in gait speed, step length, and PFS testing between moderate impairment versus healthy peers and mild impairment. A difference (P = 0.045) in step length and a trend towards significance (P = 0.064) for PFS was found between healthy peers and mild impairment group. This study revealed that PwP with mild impairment also have significant changes in step length and trends toward plantarflexor weakness without a significant difference in gait speed. These early changes may warrant early assessment and intervention to prevent decline. This study may bring clinical focus onto the plantarflexor and step length for early comprehensive assessment and treatment of gait and mobility for PwP.

DiPasquale, J., Trammell, M., Clark, K., Fowler, H., Callender, L., Bennett, M. and Swank, C. (2021). “Intensity of usual care physical therapy during inpatient rehabilitation for people with neurologic diagnoses.” Pm r Feb 18. [Epub ahead of print].

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INTRODUCTION: Early, intense rehabilitation is essential to promote recovery after stroke, spinal cord injury (SCI), and traumatic brain injury (TBI). However, intensity of usual care rehabilitation interventions during inpatient rehabilitation are poorly characterized. OBJECTIVE: We described the intensity of usual care rehabilitation interventions completed during the subacute phase of recovery from neurologic injury. DESIGN: Observational. SETTING: Inpatient Rehabilitation Facility. INTERVENTIONS: 22 usual care physical therapy interventions were grouped into 6 categories: gait (4 activities), functional (2), strengthening (4), aerobic (6), balance (4), and wheelchair (2). PATIENTS: Patients admitted to inpatient rehabilitation with a primary diagnosis of stroke, SCI or TBI within 6 months of injury. MAIN OUTCOME MEASURE(S): Cardiovascular intensity (physiological and perceived) was recorded during rehabilitation activity sessions. Physiological intensity was assessed by heart rate response (HRR) via a Polar A370 Fitness Watch and characterized as very light (<30%), light (30%-39%), moderate (40%-59%), vigorous (60%-89%), and near maximal (≥90%). Perceived intensity was assessed using the Rate of Perceived Exertion scale (RPE). RESULTS: Patients [stroke n = 16 (number of activity sessions = 388 / average session duration = 15.1 minutes); SCI n = 15 (299 / 27.3 minutes); TBI n = 15 (340 / 13.4 minutes)] participated. For patients with stroke, moderate-to-vigorous HRR was attained between 42% (aerobic exercise) to 55% (wheelchair propulsion) of activity sessions. For patients with SCI, moderate-to-vigorous HRR was attained between 29% (strength training) to 46% (gait training) of activity sessions. For patients with TBI, moderate-to-vigorous HRR was attained between 29% (balance activities) to 47% (gait training) of activity sessions. Associations between HRR and RPE were very weak across stroke (r = 0.12), SCI (r = 0.18), and TBI (r = 0.27). CONCLUSIONS: Patients with stroke, SCI, and TBI undergoing inpatient rehabilitation achieve moderate-to-vigorous intensity during some usual care activities such as gait training. Patient perception of intensity was dissimilar to physiological response.

Shearin, S.M., Medley, A., Trudelle-Jackson, E., Swank, C. and Querry, R. (2020). “Plantarflexor strength, gait speed, and step length change in individuals with Parkinson’s disease.” Int J Rehabil Res Oct 16. {Epub ahead of print].

Full text of this article.

Parkinson’s disease affects the ability to walk often resulting in decreased independence and low quality of life. The purpose of this study was to examine differences in plantarflexor strength (PFS), gait speed, and step length in persons with Parkinson’s disease (PwP) and healthy peers using clinical measures. A secondary purpose was to examine the relationship between these gait components across disease severity. The study was a convenience sample of 71 PwP and 25 community healthy peers. Outcome measures included 10-Meter Walk, step length, and Calf-Raise Senior Test. PwP were separated into mild and moderate impairment groups using the Movement Disorders Society United Parkinson’s Disease Rating Scale Motor Subscale. Between group differences for gait speed (F2,93 = 24.560, P = 0.000), step length (F2,93 = 21.93, P = 0.000) and PFS (F2,93 = 19.49, P < 0.000) were observed. Post hoc testing determined a difference (P < 0.00) in gait speed, step length, and PFS testing between moderate impairment versus healthy peers and mild impairment. A difference (P = 0.045) in step length and a trend towards significance (P = 0.064) for PFS was found between healthy peers and mild impairment group. This study revealed that PwP with mild impairment also have significant changes in step length and trends toward plantarflexor weakness without a significant difference in gait speed. These early changes may warrant early assessment and intervention to prevent decline. This study may bring clinical focus onto the plantarflexor and step length for early comprehensive assessment and treatment of gait and mobility for PwP.