Effect of Deep Cervical Flexor training on Respiratory Functions in Chronic Neck Pain patients with Forward Head Posture

Protruded chin posture is one of the commonly seen postural problem associated with patients having chronic neck pain. It is also known by names Forward Head Posture (FHP) or anteriorly translated head posture. The FHP causes an alteration in mechanics of rib cage which leads to a reduction in mobility of thorax and abdomen, decreased movement of the diaphragm, reduced ventilatory effectiveness of diaphragm and reduced ef icacy of abdominals and intercostals muscles during respiration. Therefore this study was executed to check the effectiveness of deep cervical lexor exercises on Craniovertebral angle and pulmonary functions. It was a comparative experimental study design. Based on the study’s selection criteria, the total numbers of 100 subjects were taken and divided into Experimental and Control groups. In-depth Cervical lexor training with the conventional Physiotherapy was given to subjects of the experimental group. Control group subjects received only Conventional Physiotherapy for six weeks. The baseline measurement was taken on day one of the studies. The digital camera assessed the Forward head posture by measuring Craniovertebral Angle (CVA). Spirometry determined pulmonary functions (FEV1& FVC). All measurements were repeated at the end of the 6 week. The baseline measurement and measurement at the end of 6 week were compared by using the t-test. Considerable improvement in Craniovertebral angle and functional status of the lung, resulted in subjects who were given in-depth cervical lexor training along with the conventional Physiotherapy treatment (p< 0.05). Therefore it is suggested that deep cervical lexor exercises improve the head posture and also correct the biomechanics of respiratory muscles. Deep neck lexor training can be considered as an ef icient technique in lessening protruded chin posture.


INTRODUCTION
One of the most common problems of musculoskeletal system is continuous pain in neck that is chronic neck pain. Once in life time approx 70%-80% of people fall prey to neck pain and in approx 60% of people either pain persists or there are repeated episodes of pain. Since long neck pain was given less priority compared to pain in back (Jull et al., 2008). However, the increasing incidence of neck pain during this century, which can be justi ied by changes owing to increase used of gadgets & mod-ernization has led to increased prevalence of pain in neck. Thishas led to a continuously growing interest and research regarding the clear understanding of causes, manifestations and management of neck pain. Patients with FHP are associated with muscular imbalance around cervical and thoracic spine (Harman et al., 2005).
Positioning of head is believed to be associated with initiation of Neck Pain, and few therapists focus its value at the time of evaluation (Silva et al., 2009). Anterior positioning of head or chin protrusion is one of frequently seen deformities identi ied with Neck Pain. This can also be de ined as much forward bending of neck in sagittal plane where in head protrudes forwarded (Yip et al., 2008). It is regarded to be associated with increased extension insuperior segment of cervical spine and demolishing of inferior portion of cervical spine with stretched and weak retractors of scapulae (Harman et al., 2005). It has been found that Chronic pain in neck has become one of the common problems of muscular & skeletal system affecting more & more number of people. Chronic neck pain has been found to be associated with decreased hand grip strength (Pawaria et al., 2019b). Patients with neck pain present with complaints related to musculoskeletal system like fatigue of cervical musculature. Hypomobility, impaired position sense, abnormal posture and lung functions and psychological compromise are also seen in patients with neck pain (Kapreli et al., 2008).
Disrupted mobility, faulty mechanics of diaphragm is also observed in these patients. There is increased activity of accessory muscles like sternocleidomastoid, elevated rib cage, reduced thoracoabdominal mobility leading to reduced ef iciency of diaphragm. The alteration in kinetics and kinematics of respiratory system leads to reduced strength of respiratory muscles which further effects chest expansion and hence all major respiratory functions (Okuro et al., 2011).
Variety of interventions which includes stretching, strengthening exercises, and biofeedback have been suggested by researchers for patients with chronic neck pain (Yip et al., 2008). Speci ic exercises include stretching of upper cervical extensors, pectorals and strengthening of deep cervical muscles and shoulder retractors. These exercises help in improving neck posture by correcting muscular imbalance that develops in patients with forward head posture (Kendall et al., 1993).
Studies have reported deep cervical lexor training to be an important component of treatment of patients with prolonged neck pain as the training addresses impaired physiological and neuromuscu-lar function of cervical spine (Dusunceli et al., 2009).
Chan Woo Nam et al studied on the ef icacy of neck stabilization exercises and breathing training on lung functions in stroke patients. They found that the patient with cervical stabilization exercises in adjunct with breathing retraining showed greater improvement in respiratory functions (Nam et al., 2015). The current study intended to investigate role ofdeep cervical lexion exercisein combination with routine Physiotherapy sessions on pulmonary functions in patients with anteriorly translated head posture. The entire data collection was done in Medicine OPD of SGT Hospital with prior permission. G-power software was utilized for calculation of sample to be included in the study. Power of study was kept 95%.

MATERIALS AND METHODS
Subjects that were included for the study had neck pain since > 6 month; they were in the age group of 20-40 years and had disability ranging within score of 5-15 according to Neck Disability Index (NDI) and were unable to achieve target of 24 mm of Hg on Sphygmomanometer in deep cervical lexion test (Thangavelu and Moorthy, 2014).
Patients with neck pain of traumatic origin, vertebral column anomalies, any history of spinal surgeries and with Body Mass Index in category of overweight were excluded from the study.
All the patients were allotted to Group A or Group B by simple random allocation method with 50 subjects in each group. Group A (Experimental Group) received Deep Cervical lexion training with the Conventional Physiotherapy treatment. Group B which was the control group was given routine Physiotherapy treatment. All the subjects underwent baseline assessment for pulmonary functions (FEV 1 & FVC) & Craniovertebral angle was measured to assess forward head posture. Whole course of action of treatment program was described to all subjects. A signed written informed consent was taken from subjects.

Procedure
Conventional Physiotherapy treatment was given to the subjects of control group for 6 weeks which included isometric training for neck muscles, TENS and hot pack. A 30 minutes duration was selected with beat frequency and the amplitude was kept between 10-30 mA. Cervical isometric were executed for all cervical muscles in sitting position with contraction duration of 10 sec with 15 sec of rest between holds. All exercises were repeated 10-15 times (Dusunceli et al., 2009).
Experimental group (Deep cervical lex or training + Routine Physiotherapy treatment)

Steps,
1. All patients were asked to lie down in supine position 2. Cuff of sphygmomanometer was kept under occiput 3. Subjects were guided to reach a pressure of 20 mm Hg on sphygmomanometer and then gradually increment to 2 mm Hg pressure to inally reach target of 30 mm of Hg in ive progressive position of neck lexion.
IBM SPSS 21 Multilingual software was used for comparison of baseline measurement and measurement at the end of 6 th week.

RESULTS AND DISCUSSION
For analyzing data SPSS 21 window version was used. Signi icance levels was kept < 5%. Student t-test was used for measuring changes between the groups. Table 1 shows both groups were homogenous at baseline. Analysis within groups was done by using related t-test. Signi icant differences were found in both the groups when the outcomes measures were compared (pre intervention and post intervention) within the groups (Tables 2 and 3 &Figures 1 and 2 ). A signi icant difference was seen between Group A& Group B on 6 th week with experimental group performing better compared to other group Table 4.
In the study researchers intended to investigate ef icacy of deep cervical lexor training combined with traditionally given Physiotherapy interventionon the pulmonary functions in subjects suffering from neck pain which is chronic in nature and is associated with anteriorly translated head posture. Forward head posture causes anterior positioning of head that increases normal anterior cervical convexity and exaggerated cervical lordosis. The anterior slanting of the headresults into compression of posterior spinal structures including facet capsules and spinal disks. The muscular imbalance that results causes ischemia of cervical and upper back muscles over a period of time which is trying to counterbal-  The forward head posture is accompanied by shortening of joint capsule in posterior part of the zygoapophyseal joint leading to narrowing of intervertebral foramen and may cause nerve root compression. These all are the potential sources of neck pain in patients with FHP. In addition, medial rotation of scapulae, development of kyphosis in thorax region occurs in FHP which leads to diminished thoracic capacity resulting into lowered in vital capacity of lungs (Pamela et al., 2005). It is believed that anteriorly translated head posture leads to reduced excursion of rib cage speci ically lower portion which affects mechanics of breathing. The ef icacy of diaphragm and strength of respiration muscles is also reduced (Szczygiel et al., 2015). A study reported that subjects having forward head posture had reduced activity in accessory muscles of respiration as compared to normal subjects (Han et al., 2016). A research reported that exaggerated cervical lordosis to be responsible for reduced vital capacity in patients with FHP (Lee et al., 2011).
Studies have found posture correction exercise along with deep neck muscles strengthening have    been found to be effective in improving cervical angle and enhanced respiratory functions (Lee et al., 2017). Another study reported SNAGS to be effective in improving pulmonary status in subjects with protruded chin posture (Kim et al., 2015). Neck stabilization exercises are found to be effective in patients with FHP (Noh et al., 2013).
A study reported inclusion of cervical stabilization exercises into conventional treatment to be effective in reducing chronic neck pain (Dusunceli et al., 2009). Similar results were reported by Akodu AK et al. Patients were bene itted in terms of psychological symptoms like depression & anxiety associ-ated with their neck pain. Suppression of pain pathways in brain due to enhanced stimulation of motor pathways and improved functional status of patients have also been reported by researchers (Akodu et al., 2018).
It is reported that deep cervical lexor exercises are helpful not only in reducing neck pain but also improving strength of respiratory muscles, craniovertebral angle in patients with chronic neck pain and respiratory status of patients (Kalra et al., 2017). Neck stabilization training given with feedback was also found to improve the respiratory status in patients suffering from chronic neck pain (Pawaria et al., 2019a).
It was found that subjects who received the deep cervical lexor training with the conventional Physiotherapy program bene itted more. Results of this study suggested that reduction of forward head posture with cervical stabilization exercises improve pulmonary functions by correcting the altered biomechanics of cervical and thoracic spine which in turns improve the thoracoabdominal mobility and ef icacy of diaphragm.

CONCLUSIONS
Inclusion of deep neck lexor training in treatment regimen of patients with chronic pain helps in reduction of forward head posture by reducing craniovertebral angle (CVA) and thereby improves the respiratory function in terms of FVC and FEV 1 by improving the mechanics of respiration. Therefore, it is concluded that deep cervical training should be included in the rehabilitation program of chronic neck pain patients with forward head posture.