CRITICALLY APPRAISED PAPER (CAP) Kapadia, N. M., Zivanovic, V., Furlan, J. C., Craven, B. C., McGillivray, C., & Popovic, M. R. (2011). Functional electrical stimulation therapy for grasping in traumatic incomplete spinal cord injury: Randomized control trial. Artificial Organs, 35(3), 212 216. https://doi.org/10.1111/j.1525-1594.2011.01216.x CLINICAL BOTTOM LINE This study was specifically aimed to assess the short-term and long-term effectiveness of functional electrical stimulation (FES) therapy on improving upper limb function for individuals with a subacute traumatic C4 C7 spinal cord injury. The participants in this study demonstrated decreased hand function, in particular the inability to manipulate and grasp objects. The evaluators measured the impact of FES therapy on an individual s task performance and hand function. Although the researchers in this study found FES to be an effective rehabilitation approach and suggested long-term effectiveness after discharge, the results and study design are inconsistent and unclear, which therefore diminishes the strength and reliability of these conclusions. The researchers findings align with previous evidence that supports the use of FES therapy in a clinical setting. As mentioned, however, this study has room for improvement. The authors should increase the rigor and validity of future studies by addressing the multiple biases and limitations that are present here. Occupational therapy practitioners can benefit, however, from using the information found in this study and previous studies on FES therapy to further advance their clinical knowledge. This intervention may serve as an effective supplemental approach in helping promote arm hand function among patients with different spinal cord injuries. Similar FES techniques may also be effective in increasing arm hand function for patients who present with an amputation or demonstrate stroke symptoms, such as upper extremity hemiparesis. FES therapy may also have the potential to increase functional movements for individuals who present with multiple sclerosis or cerebral palsy. 1
FES therapy also allows occupational therapists to affect a patient s recovery earlier on in the process, by letting individuals participate in function before they can voluntarily do so themselves. By introducing functional movements at an earlier stage, FES provides patients with motivation for therapy and ensures faster independence, allowing them to return to their occupational roles in less time. Overall, FES therapy has the potential to significantly improve lives and correlates directly with the goal of occupational therapists to promote functional engagement and life satisfaction. More research is needed, however, to further our clinical knowledge of the effectiveness of FES therapy and its ability to improve an individual s upper extremity function. Major limitations that should be addressed by these researchers in the future include the lack of power analysis that was used to determine the sample size, the lack of clarity regarding the procedural process and specific measures taken to eliminate biases, and the inconsistent representation of results. By addressing these limitations, the researchers will be able to ensure a more reliable and rigorous study. RESEARCH OBJECTIVE(S) Examine the short-term and long-term benefits of FES therapy on increasing hand function among adults with an incomplete subacute C4 C7 spinal cord injury DESIGN TYPE AND LEVEL OF EVIDENCE Level II: Nonrandomized controlled design (cohort design) Although the authors reported that this study is a Level I (randomized controlled trial), the process of the study lacks the rigor that is expected of a Level I procedure, and therefore the study should be lowered to a Level II design. PARTICIPANT SELECTION How were participants recruited and selected to participate? Where and how the participants were recruited were not stated. The researchers assessed potential participants on their type of injury, level of injury, duration postinjury, and ability to grasp. Participants with a subacute traumatic spinal cord injury from C4 to C7 who were unable to grasp and manipulate objects were invited to participate in the study. Inclusion criteria: Not identified Exclusion criteria: Not identified 2
PARTICIPANT CHARACTERISTICS N= 22 #/ % Male: 17/77% #/ % Female: 5/23% Ethnicity: Not identified Disease/disability diagnosis: Primary subacute spinal cord injury from C4 to C7; secondary decreased hand function INTERVENTION AND CONTROL GROUPS Group 1: Control group Brief description of the intervention How many participants in the group? Where did the intervention take place? Who delivered? How often? For how long? Group 2: Experimental group Brief description of the intervention The control group received one dose of conventional therapy after baseline assessments were completed. Their sessions consisted of routine use of strengthening and stretching exercises as well as routine practice of activities of daily living (ADLs). 12 participants Single site presumed, not identified Occupational therapists; consistency not specified 5 days/week (60-minute session/day) 8 weeks of conventional therapy (40 sessions total) The experimental group received one dose of FES therapy after baseline assessments were completed. Participants receiving FES therapy performed ADLs while being assisted with electrical stimulation. Four stimulation parameters were used: balanced, biphasic, current-regulated electrical pulses; pulse amplitude from 8 to 50 ma (typical values 15 30 ma); pulse width of 250 ms; pulse frequency of 40 Hz. How many participants in the group? Where did the 10 participants Single site presumed, not identified 3
intervention take place? Who delivered? How often? For how long? Occupational therapists; consistency not specified 5 days/week (60-minute session/day) 8 weeks of FES therapy (40 sessions total) INTERVENTION BIASES (Check yes or no, and include a brief explanation) Contamination: NO Co-intervention: Timing of intervention: Site of intervention: The researchers clearly identified that all participants were randomized into two groups; the intervention group received FES therapy, and the control group received conventional occupational therapy. The study did not identify whether participants received additional interventions at the time of the study, such as the use of medications. Therefore there is a potential for bias. The time of day was not specified; therefore, inconsistent timing of intervention between participants might have led to biased results if participants were fatigued, for example. We can presume that the intervention was performed at a single-site rehabilitation center, as implied by the authors in the abstract and introduction; however, the site of the intervention was not explicitly stated. Use of different therapists to provide intervention: The researchers identified that the same amount of attention was given to both groups. The consistency of therapists and the number of different therapists used, however, were not identified, and therefore there is a potential for bias. Baseline equality: Baseline data show that the study had significantly fewer female participants compared with male participants, with a 5:17 ratio. MEASURES AND OUTCOMES Measure 1: Functional Independence Measure 4
Name/type of measure used: What outcome is measured? Is the measure reliable (as reported in the article)? Is the measure valid (as reported in the article)? When is the measure used? Functional Independence Measure (FIM) The FIM measures an individual s level of disability and indicates the amount of assistance he or she needs to perform ADLs. Not Reported Not Reported At baseline, postintervention (8 weeks), and follow-up (6 months) Measure 2: Spinal Cord Independence Measure Name/type of measure used: What outcome is measured? Is the measure reliable as reported in the article? Is the measure valid as reported in the article? When is the measure used? Spinal Cord Independence Measure (SCIM) The SCIM measures task performance among individuals with a spinal cord injury. Not Reported Not Reported At baseline, postintervention (8 weeks), and follow-up (6 months) Measure 3: Toronto Rehabilitation Institute Hand Function Test Name/type of measure used: What outcome is measured? Is the measure reliable as reported in the article? Is the measure valid as reported in the article? Toronto Rehabilitation Institute Hand Function Test (TRI-HFT) The TRI-HFT is an objective measure intended to assess hand function. It specifically measures manipulation and grip force. Not Reported The TRI-HFT is stated as reliable, as found by the researchers in this study. The measures and statistics are unpublished, however. Not Reported The TRI-HFT is stated as valid, as found by the researchers in this study. The measures and statistics are unpublished, however. 5
When is the measure used? At baseline, postintervention (8 weeks), and follow-up (6 months) MEASUREMENT BIASES Were the evaluators blind to treatment status? NR Was there recall or memory bias? NR Blinding was not identified in this article; therefore, there is a potential for bias. The article did not specify whether participants had experience with FES therapy in the past; therefore, there is potential for recall or memory bias. Other measurement biases: (List and explain) NA RESULTS List key findings based on study objectives: After treatment (8 weeks), both groups significantly improved their upper extremity functions compared with baseline measurements. The intervention group (FES therapy) showed significantly greater functional improvement, as measured with FIM self-care scores (p =.015), SCIM upper extremity subscores (p <.0001), and TRI-HFT total score for manipulation of Objects 1 to 10 (p =.054), when compared with the control group. Five individuals (control group: n = 1; experimental group: n = 4) were present at follow-up (6 months). All 4 participants of the intervention group either continued to improve or maintained improved upper extremity function, as measured with FIM self-care subscores and SCIM self-care subscores. The TRI-HFT at follow-up (6 months) measured 3 of the 4 individuals in the intervention group. Their scores demonstrated trends similar to those seen on the FES self-care subscore and SCIM self-care subscore. Additional results from the control group were not reported. 6
Was this study adequately powered (large enough to show a difference)? NO The rigor of this study was significantly reduced by the small sample size and lack of power analysis. Without an adequate sample size, the researchers could not eliminate the possibility of chance or prove that FES therapy was significantly responsible for the increase in voluntary hand function among participants with a subacute traumatic C4 C7 spinal cord injury. Were the analysis methods appropriate? All analyses are consistent with standard statistical analysis methods. The study used a nonparametric, nonpaired t test to compare the means of the intervention group with the control group at baseline. It then used a linear regression to examine the relationships among all three outcome variables and the results of both groups at discharge. Were statistics appropriately reported (in written or table format)? NO Data and analyses were provided in written and table format; however, they were unclear and insufficient because they lacked statistics. Was participant dropout less than 20% in total sample and balanced between groups? YES NO Only 5 participants remained, which resulted in a 77% dropout rate at the follow-up measurements performed 6 months after discharge from the intervention. What are the overall study limitations? By attempting a Level I, randomized controlled trial, the researchers worked to address potential biases. This study still lacked the degree of rigor that is expected of a Level I procedure, however, and should be considered a Level II design because of the numerous limitations that failed to address reliability and validity concerns. For example, the researchers failed to identify the potential for cointervention bias, the possibility of inconsistent timing, the lack of blinding, and the inconsistent use of therapists as possible study limitations. The researchers also failed to identify how they recruited their participants, where the intervention took place, how participants were randomized, whether participants had experience receiving FES therapy, and whether there was potential for recall or memory bias. These limitations as well as baseline inequality results all serve as study limitations and decrease the rigor of this study. Additional barriers of this study might include the small sample size, which could be the result of a lack of power analysis; an absence of standardized outcome assessments; and unclear and inconsistently reported results. These barriers each contributed to the study s inability to produce significant results and prove the effects of FES therapy on increased hand function for individuals with a subacute C4 C7 spinal cord injury. Last, the presence of attrition greatly affected this study by decreasing the sample size even more and limiting the researchers ability 7
to generate short-term and long-term effects. CONCLUSIONS State the authors conclusions related to the research objectives. The authors concluded that the use of FES therapy in combination with task-specific conventional occupational therapy was more effective in improving upper extremity function for individuals with subacute traumatic spinal cord injuries than the use of occupational therapy alone. They also concluded that individuals using FES in combination with task-specific occupational therapy showed significant improvements in hand function after an 8-week intervention phase as well as signs of improved and maintained function up to 6 months after intervention. FES is a simple approach that can be easily incorporated into occupational therapy interventions and involves minimal training to administer. These conclusions are reasonable; however, further research is necessary to increase the rigor of this study and produce significant results that are also consistent, reliable, and valid. This work is based on the evidence-based literature review completed by Mackensie Menke, OTS, and Christine McConnell, DC, OTR/L, faculty advisor, College of St. Scholastica. CAP Worksheet adapted from Critical Review Form Quantitative Studies. Copyright 1998, by M. Law, D. Stewart, N. Pollack, L. Letts, J. Bosch, & M. Westmorland, McMaster University. Used with permission. For personal or educational use only. All other uses require permission from AOTA. Contact: www.copyright.com 8