|Year : 2020 | Volume
| Issue : 1 | Page : 47-54
Effect of functional strength training versus proprioceptive neuromuscular facilitation on balance and gait in patients with diabetic neuropathy
Janhavi Jagdish Atre, Suvarna Shyam Ganvir
Department of Neurophysiotherapy, DVVPF'S College of Physiotherapy, Ahmednagar, Maharashtra, India
|Date of Submission||03-Jan-2020|
|Date of Decision||20-Feb-2020|
|Date of Acceptance||28-Feb-2020|
|Date of Web Publication||03-Jul-2020|
Dr. Janhavi Jagdish Atre
#3, Laxmi Residency, Lane No. 10, Dahanukar Colony, Kothrud, Pune - 411 038, Maharashtra
Source of Support: None, Conflict of Interest: None
Background: Diabetic neuropathy is one of the major complications of diabetes mellitus, which mainly affects lower limbs in patients with diabetes. Thus, taking into consideration, the debilitating effects of diabetic neuropathy, strength training (ST) is advocated for these individuals to prevent further deterioration. There is meager literature supporting the effectiveness of proprioceptive neuromuscular facilitation (PNF) in individuals with diabetic neuropathy.
Objective: The objective of this study was to compare the effectiveness of functional ST and PNF on balance and gait in patients with diabetic neuropathy.
Materials and Methods: Thirty-two participants with diabetic neuropathy were recruited and randomly allocated to PNF group and FST group. PNF group received PNF lower limb patterns and functional ST group received functional ST for 5 days a week for 8 weeks. Balance and gait were evaluated using the Berg Balance Scale (BBS) and Dynamic Gait Index (DGI) respectively.
Statistical Analysis: Within group and between groups, data were analyzed using the Wilcoxon signed-rank test and Mann–Whitney U–tests respectively.
Results: A significant improvement in the values of BBS and DGI was observed in PNF group (P < 0.05) as well as FST group (P < 0.05). When PNF and FST were compared, there was a statistically significant improvement in the FST group for both BBS (P = 0.02) and DGI (P = 0.03).
Conclusion: Functional ST is more effective than PNF in improving the clinical measures of balance and gait in patients with diabetic neuropathy.
Keywords: Balance, Diabetic neuropathy, Exercise, Functional training, Strength, Type 2 diabetes
|How to cite this article:|
Atre JJ, Ganvir SS. Effect of functional strength training versus proprioceptive neuromuscular facilitation on balance and gait in patients with diabetic neuropathy. Indian J Phys Ther Res 2020;2:47-54
|How to cite this URL:|
Atre JJ, Ganvir SS. Effect of functional strength training versus proprioceptive neuromuscular facilitation on balance and gait in patients with diabetic neuropathy. Indian J Phys Ther Res [serial online] 2020 [cited 2020 Aug 3];2:47-54. Available from: http://www.ijptr.org/text.asp?2020/2/1/47/288869
| Introduction|| |
Diabetes mellitus is a metabolic disease depicted by hyperglycemia that results from deficiencies in insulin secretion, insulin action on target tissue, or both. The chronic hyperglycemia may result in long-standing damage and failure of various organs, namely the kidneys, heart, eyes, blood vessels, and nerves. According to the World Health Organization, the rate of occurrence of diabetes mellitus in the year 2010 was as high as 5.6% in urban areas and 2.7% in rural areas of India. India being the second-most populated country in the world is on the verge of becoming diabetic capital of the world. 50.8 million was the total number of people affected with diabetes in 2010, and this number is predicted to increase to 87.0 million by the year 2030. One of the most common complications of diabetes, diabetic peripheral neuropathy (DPN) is seen in 50% of all patients with diabetes. The main characteristic feature of diabetic neuropathy is the continuing destruction of the nerves. The common symptoms of neuropathy include painful lower limbs, altered sensation such as numbness, burning, and tingling in lower limbs, reduced or absent deep-tendon reflexes, and weakness in lower limb muscles which result in the impairment of balance and gait further leading to high risk of falls. All of these symptoms can affect the activities of daily living of these individuals and consequently reduce a person's quality of life.
Patients with diabetes with peripheral neuropathy have reduced gait speed, increased stance time, decreased cadence, short stride length, and higher variability in step lengths as compared to healthy individuals. These gait deviations further escalate on irregular surfaces. A reduction in the ankle moment and ankle strength is seen in these patients. Furthermore, there is an alteration in lower limb proprioception, vibration sense, and kinesthesia, which affects tactile sensitivity and leads to locomotor insufficiency in individuals with long-standing diabetes. Weakness in the lower limb muscles leads to an increase in postural sway in standing which further manifolds the fall risk.
Previous studies which were performed aimed at individually improving sensorimotor functions in lower limbs but not on overall augmentation in the performance of the lower limbs in individuals with diabetes. Allet et al. have also found that spatiotemporal gait alterations occur due to reduction in lower limb strength and sensory issues. Due to these gait and balance impairments, patients with diabetes tend to suffer from the risk of detrimental falls.
Various exercise interventions have been used to lower these complications and improve the function of the patients with diabetic neuropathy. Exercise interventions in the form of strength training (ST), endurance training (ET), resistance training, balance training, Swiss ball exercises, etc., have been used in the earlier studies to manage the complications of diabetic neuropathy.,,,, Literature available for functional ST for diabetic neuropathy is scarce. The strengthening for lower limbs in functional positions in diabetic neuropathy may lead to faster foot reaction time to visual stimuli, improved leg strength, less sway, and a reduced risk of fall.
Proprioception is defined as “the perception of joint and body movements as well as the position of the body or body segments in space.” Isakov and Mizrahi, in their study stated that, in order to improve the ability of gait in patients with neurologic problems, clinical training of proprioception is a vital factor in the treatment. Proprioceptive neuromuscular facilitation (PNF) is one such treatment approach that takes into account the use of proprioceptive stimuli. PNF, as an intervention, is a novel concept in diabetic neuropathy. PNF as a technique has been incorporated in studies aiming to improve function in conditions such as stroke, multiple sclerosis, and cerebral palsy. PNF focuses on improving strength, coordination, and control of movements by establishing the proper balance between mobility and stability. It also aids in improving endurance through the facilitation of proprioceptors.
Since the evidence available for the use of PNF and functional strength training in diabetic neuropathy is deficient, the objective of this study was to compare two interventions, namely PNF and functional ST and find their effect on balance and gait parameters in patients with diabetic neuropathy.
| Materials and Methods|| |
The present study was an experimental study conducted on 32 participants diagnosed with diabetic neuropathy carried out for a period of 1 year from April 2018 to April 2019 in the Neurophysiotherapy Department, College of Physiotherapy, Ahmednagar, India. The sample size of 32 was calculated statistically using the probability of type 1 error (α) and expected within-group standard deviation (SD) as 5. Assuming 10% dropout rate in each group, the total sample size was calculated to be 16 in each group. Forty-four participants with diabetic neuropathy were selected using a random number table, and they were then screened for eligibility to participate in the study. Out of 44 patients with diabetes, 32 participants who met the inclusion and exclusion criteria were randomly allocated into the two study groups with 16 participants in each group [Figure 1].
The participants who scored <3 as per the Michigan Neuropathy Screening Instrument (MNSI) (a screening test for diabetic neuropathy) were included in the study. Other inclusion criteria of the study were as follows: (i) diagnosed with type II diabetes, (ii) males as well as females between the age group of 50–70 years, (iii) duration of diabetes more than 5 years, (iv) minimum of grade 3 strength in lower limbs according to Medical Research Council grading, and (v) able to stand and walk without assistance. Participants with MNSI were included in the study. Participants were not included in the study if they had any of the following: (i) any musculoskeletal disorders affecting lower limbs, (ii) diagnosed with peripheral vascular diseases, (iii) suffered from common peroneal nerve injury, and (iv) diagnosed with any other neurological disorders.
Participants diagnosed with diabetic neuropathy between the age group of 50–70 years were screened using the inclusion and exclusion criteria. A clearance from the college ethical committee was obtained for conducting the study. Written consent was obtained from the participants. The study procedure was explained to the participants. Outcome measures assessed were balance using the Berg Balance Scale (BBS) and gait using Dynamic Gait Index (DGI) in both the groups. The scores of the scales (BBS and DGI) were compared at baseline and after intervention for within groups as well as between groups.
Procedure for outcome assessment
The BBS was developed to assess the balance among elderly people with impairment in balance function by measuring the performance of functional tasks. It is one of the valid scales used for the evaluation of the effectiveness of interventions and for quantitative descriptions of function in clinical practice and research. It is a 14-item scale designed to measure the balance of the older adults in a clinical setting, and the maximum score of the scale is 56. The score between the ranges of 41–56 is considered to be low risk fall, whereas 21–40 and 0–20 are considered to be medium risk fall and high risk fall, respectively. BBS has got excellent test–retest reliability (intraclass correlation coefficient [ICC] – 0.91) and the interrater/intrarater reliability is excellent (ICC – 0.97). It has excellent correlation with DGI (r = 0.67).
DGI assesses a person's ability to modify balance while walking in the presence of external demands. DGI is performed with a marked distance of 20 feet either with or without assistive devices. The scoring is based on a 4-point scale, and the highest possible score is 24 points.
DGI score between 21 and 24 depicts safe ambulatory, whereas score of <21 is predictive of falls. The DGI exhibits high reliability with excellent inter-rater (ICC – 0.82) and intra-rater reliability (ICC – 0.89) DGI is also validated with other balance and mobility scales (concurrent validity).
Procedure for intervention
This study was conducted for 5 days a week for 8 weeks on individuals with diabetic neuropathy. The intervention was delivered by a trained therapist who also performed the initial and final assessment and measured the outcomes. A brief warm-up period of 5 min was given to the patients that included stretching of Achilles tendon and Hamstrings and ROM exercises for lower limbs. Ten repetitions of ankle dorsiflexion and plantarflexion movements were given followed by knee flexion and extension and hip flexion and abduction for both the lower limbs. The entire warm-up exercise sessions were performed actively by the participants.
The FST group received training for 30–35 min per se ssion for 5 days a week which included active exercises. The exercises performed were as follows: sit to stand (10 repetitions from chair for 3 sets), walking up and down a ramp (6 laps), stair climbing (1 stair case-12 steps, 6 laps), and mini hops (10 repetitions) [Figure 2], [Figure 3], [Figure 4], [Figure 5].
The PNF group received PNF patterns with manual resistance. Three sets of PNF patterns for lower limbs (D1 flexion and extension and D2 flexion and extension pattern). 1 set consisted of 5 repetitions. A stretch to the dorsiflexors or plantar flexors of the ankle was applied initially depending on the pattern, and manual resistance was applied throughout the range of the pattern. The total duration of intervention was 35–40 min [Figure 6], [Figure 7], [Figure 8], [Figure 9].
Statistical analysis was performed using the GraphPad InStat version 3.06 (Graphpad software San Diego, California). Data were expressed as mean ± SD. Normality distribution of the data was analyzed using the Kolmogorov–Smirnov test. Baseline characteristics such as age and duration of diabetes passed the normality test. Hence, the paired t-test was used to compare these parameters between both the groups. Since the data for outcomes did not pass the normality test, within- and between-group analyses were done using the Wilcoxon's signed-rank test and Mann–Whitney U–test, respectively. P <0.05 was considered statistically significant (P < 0.05).
| Results|| |
The mean age of the participants and duration of diabetes between the PNF and FST groups were not statistically significant indicating similar demographic characteristics [Table 1].
|Table 1: Distribution of participants according to age and duration of diabetes in functional strength training and proprioceptive neuromuscular facilitation groups|
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When pre- and post-intervention values for PNF group were compared, P value was found to be statistically significant depicting the improvement in the outcomes of balance (P = 0.04) and gait (P = 0.03) post-PNF intervention [Table 2]. Similarly, when pre- and post-intervention values for functional ST group were compared, statistically significant thus showing the improvement in the outcomes of balance (P = 0.02) and gait (P = 0.04) postfunctional ST [Table 3].
|Table 2: Comparison between pretreatment (baseline) and posttreatment mean values of the Berg Balance Scale and Dynamic Gait Index of the proprioceptive neuromuscular facilitation group|
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|Table 3: Comparison between pretreatment (baseline) and posttreatment mean values of the Berg Balance Scale and Dynamic Gait Index of the functional strength training group|
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The postintervention values of BBS and DGI were compared between PNF and functional ST group. P value for BBS and DGI was found to be 0.02 and 0.03, respectively, indicating statistically significant results for FST [Table 4] and [Figure 10].
|Table 4: Comparison between functional strength training and proprioceptive neuromuscular facilitation groups on the Berg Balance Scale and Dynamic Gait Index before and after treatment|
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|Figure 10: Comparison between functional strength training and proprioceptive neuromuscular facilitation groups for Berg Balance Scale and Dynamic Gait Index before and after treatment|
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| Discussion|| |
Patients with DPN show a high risk of fall because of impaired balance and proprioception. Therefore, designing an appropriate intervention so as to overcome the complications of diabetic neuropathy and improving their function is essential. FST involves the activities in everyday life given with the focus of improving the strength of muscles. PNF also involves diagonal functional patterns. Hence, this study was conducted to determine the effects of PNF as well as FST on balance and gait in patients with diabetic neuropathy.
The prevalence of neuropathy symptoms is more in diabetes patients when the duration of diabetes is more than 5 years. The duration of diabetes also has a major effect on peripheral nerve function. This further leads to affection in nerve conduction velocity, leading to the impairment of balance and gait function in diabetic neuropathy.
The results of the current study showed a significant improvement in balance and gait in both the PNF group as well as FST group after interventions. PNF incorporates the use of proprioceptive, auditory, and cutaneous input to produce functional improvement in motor output. The purpose of giving PNF patterns of facilitation in our study was to improve the balance and gait components by improving the strength in the lower limb muscles. This improvement in the strength can be attributed by the work of stretch reflex and corticospinal tracts. Through the use of patterns in PNF, it is possible for the patient to learn the desired motor response and integrate that response into daily functional activities. The significant improvement found in the study for functional balance may be attributed to the improvement of mechanoreceptors activation thus leading to improvement in joint and kinesthetic sensation.
There have been studies which assessed the effect of PNF patterns on improving the symptoms of diabetic neuropathy. In a study by Singh et al., PNF patterns for lower limbs (D1 and D2 flexion and extension) were given for a period of 3 months. It was found that the diagonal patterns of PNF were instrumental in improving strength as well as sensations in the lower limbs of patients with diabetic neuropathy. This improvement was observed to a significant extent after the intervention of 3 months in these patients with diabetes. Chitra and Das studied the effectiveness of PNF on core strength in type 2 diabetic individuals and found that there was a significant improvement in the core strength following the intervention. This improvement in the core strength might be due to the dynamic nature of the PNF exercises.
Similarly, for the FST group, there was a significant improvement in the components of BBS and DGI following FST exercises. ST prevents muscle loss, it also improves intermuscular and intramuscular synchronization through neural control, contributing to improved stability and therefore gait. One possible explanation of the positive effects of ST on insulin resistance may be the increase in the number of glucose transporter (GLUT) proteins. In skeletal muscle cells, GLUT4 is thought to be responsible for insulin and contraction-stimulated glucose transport in the skeletal muscle. In addition, increasing total muscle mass will ultimately result in an increase in total insulin-mediated glucose uptake. Another underlying mechanism for improved glucose uptake could be an increased number of insulin receptors in the muscle cell.,,
Cauza et al. conducted a study to compare the effects of a 4-month ST versus aerobic ET program in participants with type 2 diabetes mellitus. They found a significant reduction in blood glucose and glycosylated hemoglobin in the group that received ST and concluded that ST was better than ET in all metabolic parameters and recommended ST for the treatment of type 2 diabetes mellitus.
As seen in the results, there was a significant improvement in the values of BBS and DGI for the FST group than PNF group after intervention. In standing position, there is cocontraction of agonist and antagonist muscles, leading to balancing of the body. This balancing action of lower limb muscles seen in the standing position leads to erect standing. In diabetic neuropathy, due to the affection of sensory and motor nerves, there is impairment in balancing forces of the lower limbs and loss in proprioception. Thus, functional ST in the standing position must have challenged the balance of these patients thus imposing demands on lower limb muscles. The muscles may have counteracted for loss of proprioception thus leading to improvement in balance.
Walking is a highly integrated function that requires the harmonized involvement of many physiological subsystems of the body. ST exercises increases muscle work in lower limbs, which can be considered a key factor in reducing gait alterations in diabetic people. The use of standing position in FST may have improved proprioception due to weight bearing (WB) on lower limbs which further leads to improvement in balance and gait. Mueller et al. compared WB versus nonweight-bearing (NWB) exercises in patients with diabetes. Intervention given was group specific and consisted of exercises conducted in sitting or lying (NWB) or standing and walking (WB). At the end of intervention, there was a significant improvement in WB group than NWB group.
This study had some limitations. Only, blood sugar levels of participants were taken into consideration before giving intervention. Due to the fact that the present study was self-funded and because of the higher costs involved, glycosylated hemoglobin was not considered. The future scope of the study would be a combination of PNF patterns in standing position given to patients with diabetic neuropathy. These sorts of exercises can be formulated, and the effect can be evaluated in patients with diabetic neuropathy.
| Conclusion|| |
Both functional ST and PNF improve the outcomes of balance and gait in diabetic neuropathy. However, functional ST is more effective than PNF in improving the outcomes of balance and gait in patients with diabetic neuropathy. PNF patterns along with functional ST can be incorporated in the intervention for individuals with diabetic neuropathy.
Declaration of patient consent
The authors certify that they had obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflict of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10]
[Table 1], [Table 2], [Table 3], [Table 4]