Keywords
DNS - rehabilitation - neurological conditions - dynamic neuromuscular stabilization
- quality of life
Introduction
Neurological conditions, both fatal and nonfatal, are significant contributors to
the global burden of communicable and noncommunicable diseases.[1] Disability-adjusted life years serve as an important metric for evaluating the global
burden of neurological conditions, and their prevalence continues to rise worldwide.[1] Neurological conditions impact the central nervous system such as nerves, brain,
and spinal cord. Individuals with these conditions face various sensory, motor, cognitive,
and functional challenges, reducing overall quality of life.[1]
Cerebrovascular accidents (CVAs)/stroke involve a sudden, focal interruption or obstruction
in the cerebral blood flow, leading to neurological deficit. The most common type
is ischemic typically caused by embolism or thrombosis.[2] Neurodegenerative disorders influence balance, motor control, speech, respiratory
and heart functions, reading abilities and cognition.[2] Diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's
disease, ataxia, and motor neuron disease fall under this category.[2] AD leads to dementia. Pain, memory, thinking, gait, and balance deficits are common
in patients with AD, with a of prevalence rate of nearly 60%.[3] PD progresses slowly and is characterized by tremors, bradykinesia, and problems
in gait and posture. Huntington's disease is a genetic movement disorder characterized
by progressive degeneration of the brain and neurons. Ataxia results in the loss of
motor control, coordination, and difficulties with balancing and walking.[2]
Other neurological disorders encompass pathological and traumatic disorders such as
amyotrophic lateral sclerosis, various kinds of seizures (epilepsy), traumatic brain
injury, spinal cord and peripheral nerve injuries, cerebral palsy (CP), and brain
or spinal tumors.[2] Multiple sclerosis (MS) is a central nervous system disorder, characterized by inflammation,
demyelination, and degeneration.[4] Balance dysfunction in MS presents three interrelated problems, decreased ability
to maintain position, limited and slow movements, and delayed response to postural
displacement and perturbations.[5] CP refers to a group of disorders that affect the development of movement and posture,
leading to activity limitations.[6]
[7] These are attributed to nonprogressive disturbances occurring in the developing
fetal and infant brain.[6]
[7] Children with CP may exhibit a crouched posture, delayed reflex activities, decreased
muscle activation, and spasticity.[6]
[7]
Trunk and postural control muscles, such as the abdominal muscles, are considered
important biomarkers for assessing the functional status of neurologically impaired
patients. Techniques such as proprioceptive neuromuscular facilitation and Bobath
are used to improve motor, posture, and balance control in neurological conditions,
focusing on upper limb and lower limb activities. However, there is a need for further
research to target the core to improve functionality and overall health.
Dynamic neuromuscular stabilization (DNS) is a technique developed based on the principles
of developmental kinesiology and reflex-mediated core stabilization concepts.[8] This approach focuses on facilitating core stabilizers, such as mainly the diaphragm,
obliques, and transverse abdominis (TrA), utilizing ontogenic patterns, which are
particularly helpful for individuals with reduced somatosensory function or impaired
movement awareness.[8] DNS therapy involves a thorough analysis of the quality of stability and movement
to restore the integrated spinal stabilization system (ISSS) through specialized functional
exercises.[9] Ontogenic patterns activate the spinal stabilization system, restoring intra-abdominal
pressure and enhancing movement efficacy.[10] Postural stability is improved by the subconscious activation of the postural core
muscles through the strategies of facilitating motor control for posture and balance.[11]
Therefore, this updated literature review aims to identify the effectiveness of DNS in neurological conditions.
Methods
This updated literature review provides an overview of previous researches on the
effectiveness of DNS in various neurological conditions. The literature search was
carried out on PubMed, Research Gate, Google Scholar, and Scopus databases from 2014
to 2024 using keywords such as dynamic neuromuscular stabilization, reflex-mediated
DNS, neurological conditions, DNS, cerebral palsy, stroke, Parkinson's disease, MS,
neurodegenerative conditions, ataxia, Alzheimer's disease, and multiple sclerosis
with Boolean operators. We identify relevant studies by establishing inclusion and
exclusion criteria, removing duplicates, and screening titles, keywords, and abstracts
in the preliminary stage. Only full-text studies comparing the effectiveness of DNS
as an intervention in participants with neurological conditions were considered for
the inclusion criteria. Studies not written in English were excluded, and articles
on other topics like cardiovascular and musculoskeletal were also excluded from this
literature review. Any other adjunctive rehabilitation protocol included in the studies
and superimposing the effects of DNS training was also excluded from this review.
Three independent researchers H.K., A.C., and M.S. were involved in searching and
extracting the relevant data from the studies, and any differences in thought processes
were resolved through discussions.
Results
In this review, 10 articles were included for the final analysis, as shown in [Fig. 1], in which 269 participants were included. A total of 129 participants were affected
with stroke, 64 participants were affected with MS, 30 participants were affected
with AD, 30 participants were affected with PD, and 16 participants were affected
with CP. All the participants underwent the DNS rehabilitation protocol.
Fig. 1 Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) flowchart.
CVA (stroke): The therapeutic effect of neurodevelopment therapy (NDT) and DNS exercises on muscular
activity, core stability, and core thickness in stroke patients was examined in several
studies. For instance, in a clinical study in 2017, Yoon and You, recruited 10 participants,
including 5 healthy adults and 5 hemiparetic stroke patients.[12] The results showed that healthy subjects exhibited greater activation in the core
TrA, and internal oblique (IO) muscles during DNS than during NDT but less activation
in the superficial external oblique muscles, and improvement in muscle thickness and
pressure biofeedback unit (PBU) values.[12] Both healthy and stroke participants show a significant improvement, p ≤ 0.05, using ultrasound, electromyography (EMG), and PBU measurements.[12] These results support the theoretical hypothesis that selected stimulation of the
chest zones during DNS can elicit core stabilization intervening in the monosynaptic
reflexive activation system.[12] In a 2018 study by Benfiry et al, a group of stroke patients underwent an 8-week
protocol of DNS and showed significant improvement in balance and quality of life
using Berg Balance Scale (BBS) and 36-Item Short Form Survey (SF-36) compared to a
control group (p ≤ 0.05).[13] Another randomized controlled trial (RCT) was conducted in 2018, by Lee et al, to
compare the effects of conventional core stabilization and DNS on anticipatory postural
adjustment (APA) time, balance performance, and fear of falls in hemiparetic stroke
patients.[11] The study concludes that the APA, EMG of TrA/IO and erector spinae (ES), BBS, and
Trunk Impairment Scale (TIS) scores were significantly improved (p ≤ 0.008) in the DNS group compared to the conventional group and the Fall Efficacy
Scale (FES) score was also significantly improved as p ≤ 0.003 in both the groups compared with baseline data, but FES scores remained same
after the 2 years of follow-up period in the DNS group, p ≤ 0.003.[11]
In 2020, a RCT by Yoon et al compared the effects of DNS and conventional exercise
on respiratory function, fatigue, and activities of daily living in stroke patients.[14] The results revealed that the DNS group shows superior effects on respiratory function,
fatigue level, and activities of daily living as compared to the NDT group, p ≤ 0.05.[14] These results suggest that DNS was more effective than NDT as it coactivates the
diaphragm muscle effectively in hemiparetic patients.[14] Furthermore, an experimental study was conducted in 2021 by Raghuveer et al on the
effectiveness of diaphragm activation using reflex-mediated DNS on trunk function
in hemiplegia.[15] In this study, all the outcomes significantly improved in both groups compared to
the baseline data, p ≤ 0.05.[15]
In 2014, Oppelt et al conducted a case study on using spinal manipulation with DNS
care to improve the function of a post-CVA.[16] The study included a 31-year-old male with left-side hemiparesis. Chiropractic intervention
was provided for 32 weeks, with the inclusion of DNS intervention over the final 16
weeks.[16] The results showed that the integration of DNS exercises in the later 8 months significantly
improved the health outcomes and reached its plateau after 4 years of CVA.[16]
MS: In 2022, Abadi Marand et al designed a RCT protocol to assess the effectiveness
of DNS on balance and trunk stability in people with MS.[17] Subsequently, Abadi Marand et al conducted a RCT in 2023 to compare the effect of
core stabilization and DNS on balance, trunk function, mobility, falls, and spasticity
in people with MS.[18] Core stabilization training focuses on the deep abdominal muscles of the trunk and
is a regulated form of exercise aimed at facilitating proper stabilization of the
lumbar spine and pelvis for everyday tasks.[18] In contrast, DNS exercises are novel, functional rehabilitation methods designed
to improve motor activities based on human ontogenic developmental patterns.[18] The DNS group demonstrated a significant improvement in BBS score, postural stability,
activities-specific balance confidence, Timed-Up-Go (TUG) test, Multiple Sclerosis
Walking Scale-12, Modified Ashworth Scale, TIS, and fall rate (p = 0.01) compared to the core stabilization group.[18] The results suggest that DNS exercises may be more effective for people with MS
as they emphasize the ISSS, precise muscle activation, timing, and coordination, leading
to improved movement efficiency and trunk and muscle endurance as compared to the
core stabilization group.[18]
AD: In 2022, Shah conducted a quasi-experimental study on the effectiveness of DNS exercises
for patients with AD.[3] They found that patients with AD significantly improved their balance and gait parameters
after the 8 weeks of DNS exercises compared to the control group.[3] TUG test, gate velocity, step length, and step width show significant changes after
receiving the DNS exercises, p < 0.05.[3] However, the study had limitations such as a small sample size due to difficulty
accessing AD patients, a lack of long-term follow-up to examine the sustained effects
of DNS exercises, and the absence of a comparative intervention group.[3] Overall, DNS can be beneficial and can improve balance in gait parameters in patients
with AD.[3]
PD: Nosratikia et al conducted a quasi-experimental study on the effects of 12 weeks
of DNS training on balance in individuals with PD.[19] The study included 30 elderly men and women suffering from PD, who were randomly
assigned to experimental and control groups.[19] The experimental group underwent for 12 weeks with three 50-minute sessions each
week.[19] The study found significant improvement in static and dynamic balance in the DNS
group, as evidenced by foot scan and TUG test, p ≤ 0.05.[19]
CP: Two studies on the effects of DNS training on CP were found through the search conducted
in 2017. The first study focused on a 13-year-old with spastic hemiplegic CP, showing
significant improvements in balance and gait ability after 4 weeks of DNS techniques.[20] The second study, conducted by Son et al, consisted of 15 participants with spastic
diplegia CP, found that DNS intervention resulted in increased diaphragm excursion
and improved abdominal muscle activity, enhancing motor control, balance, and gait
ability in CP children using real-time ultrasound and EMG (p = 0.004).[21] Both studies support the effectiveness of DNS in improving the physical functions
and quality of life of CP patients.[21]
Posterior
cortical atrophy
(PCA): In 2015, Francio et al conducted a case report using a chiropractic spinal manipulation
with DNS and other adjunctive rehabilitation protocols on a 54-year-old male PCA patient.[22] Results showed a 60% improvement in the various outcome measures such as the health
status questionnaire, back Bournemouth questionnaire, and pain and functional improvements.[22]
Outcome measures: Several outcome measures were administered in the included 10 articles. Real-time
ultrasound, EMG, PBU, TIS, BBS, FES, SF-36, forced vital capacity, forced expiratory
volume in 1 second, maximum inspiratory pressure, maximum expiratory pressure, Fatigue
Severity Scale, Functional Independence Measure, modified Rankin scale, stroke-specific
quality of life, 10-meter walk test, Activities-specific Balance Confidence, TUG test,
Multiple Sclerosis Walking Scale-12, Modified Ashworth Scale, fall rate, postural
stability, gait velocity, step length, step width, foot scan (center of force [COF]
and ellipse area), Bruininks–Oseretsky test, and six-minute walk test.[3]
[11]
[12]
[13]
[14]
[15]
[18]
[19]
[20]
[21]
Discussion
This updated literature review aimed to evaluate the effectiveness of DNS exercises
on various neurological conditions. The review included five studies on CVAs, one
study on MS, one on Alzheimer's, one on Parkinson's, and two studies on CP. The findings
support the findings of previous researches that DNS exercises improve the quality
of life for neurological impaired patients. However, the review noted some limitations,
such as few RCTs and the presentation of low-quality evidence. A previous systematic
review was conducted and showed that DNS is an effective approach in improving musculoskeletal
and neurological conditions, while another minireview was conducted to examine the
effectiveness of DNS exercises on stroke patients and our results support the results
of the previous literature.[8]
[23]
The included articles suggest that DNS exercises can significantly improve overall
health outcomes. For stroke survivors, DNS exercises were found to enhance muscle
activation, muscle thickness, respiratory functions, balance, and gait ability. Certain
studies utilizing randomized controlled trials (RCTs) and semi-structured experimental
designs on stroke survivors have demonstrated promosing results.[11]
[12]
[13]
[14]
[15]
In patients with MS, DNS exercises showed a positive effect on spasticity, trunk stability,
balance, fall rate, walking, and activities of daily living. However, only one RCT
was found for this condition.[18]
Similarly, in patients with AD and PD, DNS exercises were found to have positive effects
on balance and walking functions. These findings were based on quasi-experimental
design studies.[3]
[19]
In the case of CP patients, the DNS rehabilitation protocol led to significant improvement
in muscle thickness and activation, balance, and walking abilities. The evidence included
both a case study and experimental studies.[20]
[21]
Overall, the DNS rehabilitation protocol, based on ontogenic development patterns,
principles of kinesiology, and reflex-mediated core stabilization concepts, has shown
potential to improve the quality of life of neurologically impaired individuals. It
may be a positive approach in rehabilitation protocols for treating such conditions.
Conclusion
The findings of this updated review indicate that the DNS rehabilitation protocol
is an effective method for improving the quality of life of patients with neurological
impairments. Further research in this area is needed to gain a better understanding
of the results, with high-quality evidence and longer follow-up periods.
