Proprioceptive Neuromuscular Facilitation-Based Physical Therapy on the Improvement of Balance and Gait in Patients with Chronic Stroke: A Systematic Review and Meta-Analysis
Nguyen P, Chou L, Hsieh Y. Proprioceptive Neuromuscular Facilitation-Based Physical Therapy on the Improvement of Balance and Gait in Patients with Chronic Stroke: A Systematic Review and Meta-Analysis. Life. 2022;12(6):882. doi:10.3390/life12060882Link to original article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9225353/
Key Points
- The systematic review and meta-analysis aimed to evaluate the effects of proprioceptive neuromuscular facilitation (PNF) on balance and gait function in patients with chronic stroke.
- Nineteen studies with a total of 532 participants were included in the analysis.
- PNF intervention led to statistically significant improvements in balance as measured by the Berg Balance Scale (BBS), Functional Reach Test (FRT), and Timed Up and Go Test (TUG).
- PNF intervention also resulted in improvements in gait velocity as measured by the 10-Meter Walking Test (10MWT).
- The findings suggest that PNF is a potential treatment strategy for improving balance and gait speed in chronic stroke rehabilitation.
- However, more high-quality research is needed to establish a consensus on the efficacy of PNF in stroke rehabilitation.
- The studies included in the analysis had some limitations, including small sample sizes and variations in intervention protocols.
- The results have implications for clinical practice, highlighting the importance of incorporating PNF into rehabilitation programs for chronic stroke patients.
- Further research is needed to explore the optimal protocols and components of PNF interventions for stroke rehabilitation.
Introduction
This systematic and meta-analytical review focuses on the effects of proprioceptive neuromuscular facilitation (PNF) on balance and gait functions in patients with chronic stroke. Stroke survivors in the chronic stage often experience long-term motor deficits, particularly in balance and gait control, which significantly impact their quality of life and increase the risk of falls and hospital admissions. While various rehabilitation strategies have been used to improve motor and gait functions after stroke, the correction of postural asymmetry and enhancement of balance control are crucial aspects of chronic stroke rehabilitation. PNF is a therapeutic approach that incorporates multiple planes of movement to improve motor output and has been widely used in the early rehabilitation of stroke patients. Although preliminary case reports and systematic reviews have suggested positive outcomes with PNF, there is limited evidence from meta-analyses of randomized-controlled trials (RCTs). This study aims to fill this gap by systematically reviewing available RCTs and quantifying the efficacy of PNF-based approaches on the improvement of balance and gait in patients with chronic stroke. By excluding patients in the acute and subacute stages, the study focuses specifically on the effects of PNF in the chronic phase of stroke recovery. Overall, this review seeks to provide a concise and up-to-date overview of the effectiveness of PNF-based training on balance and gait functions in patients with chronic stroke.
Materials and Methods
In this study, a systematic review was conducted to evaluate the effects of Proprioceptive Neuromuscular Facilitation (PNF) on balance and gait functions in patients with chronic stroke. The review followed the PRISMA guidelines and the review protocol was registered with OSF. A comprehensive search of relevant literature from 1960 to July 2021 was performed in multiple databases including MEDLINE/PubMed, PEDro, Cochrane Library, Google Scholar, CINHAL, Web of Science, and CNKI. Database-specific filters were utilized, and hand searches of reference lists were also conducted.
The inclusion criteria for the studies were adult patients (>18 years old) diagnosed with chronic stroke (more than 6 months post-stroke), studies using PNF alone or in combination with other therapies as the intervention in experimental groups, non-PNF-based interventions in control groups, studies that measured balance and gait-related changes, and studies that employed a randomized controlled trial (RCT) design. The exclusion criteria were theses, books, conference proceedings including posters and platforms, single case studies, quasi-randomized clinical trials, and qualitative studies.
The systematic review followed the recommendations of PRISMA Protocols. The results of this review will provide insights into the effects of PNF on balance and gait functions in patients with chronic stroke, aiding in the development of evidence-based interventions for stroke rehabilitation.
Screening Process
In this research paper, a systematic and meta-analytical review was conducted to examine the effects of proprioceptive neuromuscular facilitation (PNF) on the improvement of balance and gait functions in patients with chronic stroke. The initial selection of relevant studies was done through an electronic search, with two reviewers independently evaluating the titles and abstracts. Disagreements between the reviewers were resolved by a third reviewer. The methodological quality of the studies was assessed using the 11-item PEDro Scale, which demonstrated good inter-rater reliability. For studies not on the PEDro database, their quality was evaluated independently using the same scale. The risk of bias in the included trials was evaluated using the Cochrane Handbook for Systematic Reviews of Interventions. Several criteria, including randomization sequence, allocation concealment, blinding, completeness of data, and reporting of outcomes, were considered. Study characteristics, participant characteristics, interventions, trial duration, outcome assessment period, and main results were extracted from the selected studies. A meta-analysis was performed using RevMan software, and results were described. The random- effect model was used to calculate pooled effect estimates, using means, standard deviations, and the number of participants. Heterogeneity was assessed using I2 statistics. Sensitivity analysis was conducted to assess the influence of individual trials on the combined results. Pooled-effect estimates were expressed as mean differences with a 95% confidence interval. A significance level of p 0.05 was used to determine statistical significance.
Results
This systematic and meta-analytical review examined the effects of PNF on balance and gait functions in patients with chronic stroke. A total of 1253 studies were initially identified, but only 19 were included for qualitative synthesis. The evaluation instruments used in the studies included the Berg balance scale, functional reach test, timed up-and-go test, and 10-m walking test. The quality assessment of the included studies showed a range of PEDro scores, with an average score of 5.43 ± 0.62. The most common reasons for a lower score were the lack of allocation concealment and blinding. The included studies had a total of 532 participants, with a range of age and time since stroke onset. The studies selected patients with chronic stroke, and some used additional criteria such as Mini-Mental State Examination scores or the Brunnstrom scale. The duration of PNF intervention varied from 20 to 30 minutes per session, with a total of 12 to 36 sessions. Some studies investigated the effects of PNF combined with other strategies. Different PNF approaches were employed, including the pelvic pattern and sprinter and skater patterns. Significant improvements in balance and gait were reported in some studies. Outcome measures related to motor function, including the balance and gait tests, were used in all studies, and there were significant differences in balance function before and after PNF intervention and between patients receiving PNF and controls.
Berg Balance Scale
This systematic and meta-analytical review examined the effects of proprioceptive neuromuscular facilitation (PNF) on the improvement of balance and gait functions in patients with chronic stroke. The Berg Balance Scale (BBS) was used to assess balance, and significant improvements in BBS scores were found in patients receiving PNF-based intervention compared to those undergoing non-PNF interventions. Meta-analysis results showed a significant difference in BBS scores between the PNF group and the control group. In terms of the Functional Reach Test (FRT), which measures proactive balance, significant improvements were seen in the maximal horizontal distances for FRT in patients with chronic stroke after PNF-based intervention compared to pre- treatment. Meta-analyses also showed a significant change in FRT performance between the PNF group and the control group. However, there was considerable heterogeneity in the analysis, which was attributed to a specific study. After excluding that study, the overall pooled effect for FRT was enhanced, with low heterogeneity. Overall, these findings suggest that PNF interventions can lead to improvements in balance and gait functions in patients with chronic stroke.
Functional Reach Test
This systematic and meta-analytical review examines the effects of Proprioceptive Neuromuscular Facilitation (PNF) on the improvement of balance and gait functions in patients with chronic stroke. The Functional Reach Test (FRT) is used to measure the distance between the start and end positions while standing independently, raising an arm 90 degrees from the torso, and reaching out without losing balance. A greater distance on the FRT indicates better proactive balance. Out of the 19 studies included in the review, four showed significant improvements in FRT distances in patients with chronic stroke after PNF-based interventions compared to before PNF treatment. These improvements were also observed in controls after non-PNF interventions. Meta-analyses of the data revealed significant changes in FRT performance between participants in the PNF group (n=56) and controls (n=56), with a mean difference of 2.49 cm. However, there was high heterogeneity in the results due to the study by Kim et al. After excluding this study, the overall pooled effect was enhanced, with a mean difference of 3.40 cm and low heterogeneity. This review suggests that PNF interventions can lead to improvements in balance and gait functions in patients with chronic stroke, as indicated by the increased FRT distances. However, further research is needed to better understand the effects of PNF and to address the heterogeneity observed in the meta-analyses.
Timed up and Go Test
The Timed up and Go (TUG) test is a measure of balance and functional mobility. It involves sitting on an armchair, standing up, walking 3 meters, and returning to a sitting position, with scores of 10 seconds or less indicating normal mobility and balance. This systematic and meta-analytical review examined the effects of proprioceptive neuromuscular facilitation (PNF) on balance and gait improvements in patients with chronic stroke. Of the 19 studies included, 6 studies demonstrated significant differences in TUG in patients with chronic stroke after PNF-based intervention compared to before treatment and controls with non-PNF interventions. Meta-analysis results showed significant differences in TUG performance between the PNF group and controls, with PNF resulting in an average decrease in TUG time of 2.25 seconds. This analysis had low heterogeneity. Additionally, the study examined the effects of PNF on the maximal horizontal distances for Functional Reach Test (FRT) in patients with chronic stroke. Four studies showed significant improvements in FRT distance following PNF-based intervention compared to before PNF treatment and controls with non-PNF interventions. Meta-analyses revealed significant changes in FRT performance between the PNF group and controls, with an average increase in FRT distance of 2.49 cm. However, there was higher heterogeneity, primarily attributed to the study by Kim et al. When excluding this study, the overall pooled effect size was enhanced, with an average increase in FRT distance of 3.40 cm and low heterogeneity. Overall, PNF interventions showed positive effects on both TUG and FRT measures in patients with chronic stroke.
10-Meter Walking Test
The 10-Meter Walking Test (10MWT) is a performance measure used to assess gait velocity in patients with chronic stroke. It can determine functional mobility and gait ability. Good performance in the 10MWT indicates good functional mobility in individuals with chronic stroke and is considered a practical and informative functional indicator. Of the 19 studies included in the review, 5 studies found significant improvements in 10MWT performance after Proprioceptive Neuromuscular Facilitation (PNF) intervention compared to before the intervention. Additionally, there were significant differences in 10MWT performance between patients with chronic stroke who received PNF intervention and those who received non- PNF interventions. The meta-analysis results further supported these findings, as there were significant differences in 10MWT performance between the PNF group and the control group. The mean difference in 10MWT performance between the two groups was -2.15 seconds, with a 95% confidence interval of -2.87 to -1.43 seconds. The p-value was less than 0.001, indicating statistically significant differences. The analysis also showed low heterogeneity between the studies (p = 0.08, I^2 = ). Overall, the findings of this systematic and meta-analytical review suggest that PNF intervention can lead to improvements in balance and gait functions, as demonstrated by improved performance in the 10MWT, for patients with chronic stroke.
Discussion
This systematic review and meta-analysis focused on the effects of proprioceptive neuromuscular facilitation (PNF) on balance and gait functions in patients with chronic stroke. It is the first study of its kind to specifically examine PNF in the chronic stroke population. The findings suggest that PNF-based physical therapy can lead to improvements in balance and gait velocities in patients with chronic stroke. The review identified specific PNF patterns and techniques, such as sprinter and skater exercises, neck patterns, scapular and pelvic patterns, and leg patterns, that are effective in enhancing balance and gait functions. PNF interventions were found to strengthen impaired balance and gait abilities, particularly in the lateral direction. The study also highlighted the importance of core stability training using PNF to improve trunk control, gait, and balance. The duration of PNF treatment programs, with a minimum of 30 minutes per session for at least 12 sessions, was shown to be effective in enhancing balance and gait abilities. The review emphasized the correlation between balance and gait parameters in patients with chronic stroke and recommended the inclusion of PNF in routine treatment regimens for these individuals. However, the study acknowledged several limitations, including the small sample sizes and methodological variations among the included studies. Therefore, additional high-quality research is needed to establish a consensus on the clinical use of PNF for patients with chronic stroke.
Conclusions
This systematic and meta-analytical review examined the effects of Proprioceptive Neuromuscular Facilitation (PNF) on balance and gait functions in patients with chronic stroke. The study found that while the most significant recovery of movement typically occurs within the first six months after a stroke, patients with chronic stroke can still benefit from intensive therapy beyond this timeframe. The results of the review suggest that PNF-based physical therapy has statistically significant effects on the improvement of balance and gait speed in individuals at least six months after experiencing a stroke. This indicates that PNF can be a valuable approach for promoting motor recovery in patients with chronic stroke. However, the study also highlights the need for further research on the topic. While positive statistical effects were observed, more studies on neuroplasticity and rehabilitation are necessary to establish a consensus on the clinical and research significance of PNF. This includes investigating the specific components of the technique, dosage parameters, and practice conditions to better understand the relative efficacy of PNF in future meta-analyses.
In conclusion, this systematic review and meta-analysis demonstrate the potential benefits of PNF in improving balance and gait functions in patients with chronic stroke. Nonetheless, further research is needed to fully understand the extent of its efficacy and optimize its implementation in rehabilitation practices.
Opportunities for Further Research
1. Conduct further research on the long-term effects of PNF intervention on balance and gait function in patients with chronic stroke to determine the sustainability of the improvements observed.
2. Investigate the optimal duration and frequency of PNF sessions for maximizing improvements in balance and gait in patients with chronic stroke.
3. Explore the specific PNF patterns and techniques that are most effective in improving balance and gait function in patients with chronic stroke, including the pelvic pattern, sprinter and skater patterns, and neck pattern.
4. Assess the comparative effectiveness of PNF-based interventions versus other rehabilitation strategies in improving balance and gait function in patients with chronic stroke, such as cycling, treadmill walking, and functional electrical stimulation.
5. Examine the impact of PNF on other motor outcomes in patients with chronic stroke, such as muscle strength, coordination, and functional independence.
6. Investigate the potential mechanisms of action of PNF in improving balance and gait function in patients with chronic stroke, including its effects on proprioception, muscle coordination, and postural control.
7. Assess the cost-effectiveness of PNF interventions compared to other rehabilitation strategies for improving balance and gait in patients with chronic stroke.
8. Explore the use of PNF in combination with other therapeutic approaches, such as constraint-induced movement therapy or neurodevelopmental treatment, to determine if there are synergistic effects on balance and gait outcomes.
9. Conduct studies on larger and more diverse patient populations to increase the generalizability of the findings and to determine if there are specific subgroups of patients with chronic stroke who may benefit more from PNF interventions.
