The effects of conventional treatment in addition to Pilates on biopsychosocial status in chronic neck pain: A randomized clinical trial

Abstract

BACKGROUND:

Although guidelines and systematic reviews recommend the use of exercise in the treatment of chronic pain and neck pain, there are no clear recommendations for conservative treatments frequently used in clinics. The effect of supporting clinical Pilates exercises with passive physiotherapy methods on biopsychosocial status is still unknown.

OBJECTIVE:

The objective was to investigate the effects of conventional treatment (CT) in addition to clinical Pilates on pain levels, physical condition, functional status, and psychosocial status in individuals with chronic neck pain.

METHODS:

Fifty women were randomly divided into 2 groups, the clinical Pilates group (Pilates, $n=$ 25), and the group receiving CT in addition to clinical Pilates (Pilates-CT, $n=$ 25). Both groups received treatment 3 days a week for 6 weeks. The CT program involved the implementation of hot pack (HP) application, Transcutaneous Electrical Nerve Stimulation (TENS), and therapeutic ultrasound (US) to the cervical area.

RESULTS:

CT in addition to Pilates was more effective in reducing the Visual Analog Scale (at rest and during activity), Neck Disability Index, Fear-Avoidance Beliefs Questionnaire, NeckPix Scale, Hospital Anxiety and Depression Scale-depression, and Cognitive Exercise Therapy Approach–Biopsychosocial questionnaire scores ( 0.05) and in increasing the degree of change in the extension range of motion (ROM) and cervical flexor endurance values and scores in the energy parameter of Short Form-36 ( 0.05).

CONCLUSION:

CT provided in addition to Pilates was more effective in reducing pain levels, disability, fear of movement, depression levels, and negative biopsychosocial status and improving extension ROM and cervical flexor endurance, neck awareness, and the energy/vitality parameter of quality of life in individuals with chronic neck pain.

1. Introduction

Chronic neck pain is a prevalent musculoskeletal disorder that increases disability and negatively affects health and quality of life. In addition to biological factors such as age and sex, psychosocial factors such as sleep problems, anxiety, depression, lack of social support, and long-term stress are important risk factors for neck pain [1].

Cervical muscles have a major role in the normal biomechanics of the cervical region and the maintenance of spinal stability. In individuals with chronic neck pain, muscle tone increases as a protective response, which may reduce cervical range of motion (ROM) [2]. Besides limitations, the activity of deep and painful muscles decreases due to changes in neuromuscular control [3, 4], and superficial muscle activity increases to compensate for this [4, 5, 6]. Decreased flexor muscle strength [7, 8], as well as decreased deep extensor muscle activation, may reduce support for the cervical spine and cause the recurrence of pain [4].

Individuals with chronic neck pain have disabilities and low quality of life due to multiple problems in terms of both physical and mental health (anxiety, depression) [9, 10]. These psychological factors cause symptoms to become chronic and may lead the individual to feel more severe pain, disability, or fear-avoidance [11]. In addition to the severity of pain, the functional status of the person may also affect their neck awareness [12]. Individuals with chronic idiopathic neck pain have some degree of impairment in their awareness of the neck [13]. Increasing pain intensity or the chronicity of pain may trigger fear-avoidance beliefs and cause disability [14].

Due to the nature of chronic pain, complex, multifaceted, and holistic treatments are needed. Clinical Pilates, which provides mind-body unity, increases body and movement awareness by using one’s breath effectively, improves posture, muscle control, and trunk stabilization, and provides strength and flexibility balance [15]. Additionally, it can promote the activation of deep neck flexor muscles by promoting the neutral position of the cervical spine with slight upper cervical flexion at the craniocervical junction. There are conflicting results regarding the efficacy of electrophysical agents in individuals with chronic neck pain. While it is stated that the use of TENS in addition to exercise does not provide additional benefits [16], it is not clear whether the application of therapeutic US with other CT practices provides additional benefits on pain intensity, disability, or quality of life [17]. On the other hand, it has been reported that the combination of both methods might be effective in reducing pain/stress levels and improving functionality [18, 19].

In the literature, there are a few studies on Pilates exercises in the treatment of individuals with chronic neck pain. However, most of them were planned to compare the effectiveness of Pilates with other exercise methods and the effects of clinical Pilates on body awareness, fear of movement, and biopsychosocial factors have not been investigated yet. Although it has been reported that neck awareness is associated with factors such as pain, disability, anxiety, and quality of life, the effects of exercise and electrotherapy on neck awareness are unknown. Additionally, there was no study examining the effect of electrotherapy on fear of movement and fear avoidance beliefs in individuals with chronic neck pain and it is not known whether supporting active treatment methods such as Pilates exercises with passive physiotherapy modalities has an additional effect on pain level, physical condition, functional status and psychosocial status.

Guidelines and systematic reviews recommend the use of various exercises in the treatment of chronic pain and neck pain [20, 21, 22, 23]. On the other hand, it has been reported that the combined use of active, such as exercise, and/or passive, non-drug treatments, such as manual therapy, may be the most effective treatment in reducing chronic neck pain in the short term [24]. However, the use of passive treatments such as electrotherapy and thermotherapy, which are frequently applied in clinics, is not recommended as the evidence is insufficient and unclear [20, 21, 22, 23]. Therefore, the aim of our study is to investigate whether CT given in addition to clinical Pilates has an additional effect on pain levels, physical condition, functional status and psychosocial status in individuals with chronic neck pain.

2. Materials and methods

This randomized comparative study was carried out with volunteer individuals who presented to the State Hospital Physical Therapy Service (2021–2022). Fifty volunteer women aged between 18 and 65 years, who applied to the Government Hospital with the complaint of neck pain and were determined by physicians to have non-specific chronic neck pain (lasting for more than 3 months), with a pain level of 3 and above according to the Visual Analogue Scale (VAS) were included in the study. Individuals who had undergone previous surgery in the cervical region and received physiotherapy or joint injection therapy for the cervical region in the last 6 months, those who had a history of pregnancy, trauma, cancer, infectious, inflammatory, and neurological diseases, and those who were using analgesics, myorelaxants, or antidepressant drugs were excluded from the study.

Individuals who met the inclusion criteria of the study were informed about the content of the study and were asked to sign a written informed consent form before their participation. The individuals participating in the study were randomly divided into two groups in a single block order as the clinical Pilates group (Pilates, $n=$ 25) and the group receiving CT in addition to clinical Pilates (Pilates-CT, $n=$ 25) (Fig. 1). Assessments and treatments were performed by the same physiotherapist. The study was approved by the Eastern Mediterranean University Health Sub-Ethics Committee (decision date 13.04.2021, number 2021/02).

Figure 1.

Enrollment of participants.

The effect size of the difference between the Neck Disability Index (NDI) values of the experimental groups was determined to be 0.76 [25]. Accordingly, the sample size required for 95% (1$-\beta =$ 0.95) power at $d=$ 0.76 and $\alpha =$ 0.05 was calculated as 21 individuals in each group using the G*Power 3.1.9.2 program. Considering a potential data loss rate of 20%, in the planned treatment program (for time-related or other reasons), the calculated sample size was increased by 20%, and it was decided that the final sample would include 25 people in each group.

After recording the sociodemographic information of the participants, their age, weight, height, pain levels, physical, functional, and psychosocial status, and quality of life assessments were completed.

VAS, which was one of our primary outcomes, was used to assess the severity of neck pain at rest and during activity. The participants were asked to rate the severity of their pain by placing a mark on a 10-centimeter (cm) line (0 $=$ no pain, 10 $=$ unbearable pain) according to their currently experienced pain levels, and the distance of this mark to the 0 point was measured and recorded in cm [26].

For physical state assessment cervical ROM, muscle endurance and deep cervical flexor strength and endurance test were used. Active flexion, extension, lateral flexion (right-left), and rotation (right-left) ROM values of the cervical region were evaluated with a universal goniometer in a sitting position. Farooq et al. demonstrated that this evaluation method had excellent inter-rater reliability (Intraclass Correlation Coefficient (ICC)2,2 $=$ 0.79 to 0.92) [27].

In the evaluation of cervical flexor muscle endurance, the participants were lying on their back with their legs in a hooked position, while the examiner placed a hand on the occiput region. The participants were asked to lift their heads from the bed by taking a chin-tuck position. During the test, when the head of the participant touched the hand of the examiner, a verbal command was given to the participant to maintain the position. The time that the position could be maintained was measured with a stopwatch and recorded in seconds. Inter-rater reliability of this test was found to be moderate in individuals with neck pain (ICC[2,1] $=$ 0.67) [28]. To evaluate cervical extensor muscle endurance, the participants were asked to lie in the prone position with their arms at the side of the trunk and their head ahead of the bed edge. When the test started, the participant was asked to move her head away from the bed and keep it horizontal with chin retraction. The time till exhaustion was measured with a stopwatch and recorded in seconds [29]. The craniocervical flexion test (CCFT) was used to evaluate the activation and endurance of the deep cervical flexor muscles of the participants [30, 31]. In this test, the participant laid in the supine crook position while her neck was in a neutral position. Layers of towels were placed under the head if necessary to achieve a neutral position. The pressure sensor of the biofeedback device (Stabilizer, Chattanooga South Pacific) placed under the occiput was inflated to 20 mmHg to fill the space of cervical lordosis while keeping the head in a chin-tuck position. The manometer was held in such a way that the participants could see it to follow the pressure change. The test started at 20 mmHg, and it was aimed to repeat the test at 5 different pressure levels up to 30 mmHg at a rate of increase of 2 mmHg. The participants were asked to maintain 10 isometric contractions for 10 seconds at each pressure level (Fig. 2). The tests of those who could not maintain the contractions were terminated. The participants were given a rest period of 10 seconds between repetitions. As a result of the test, two different scores were obtained as the activation score (AS) and the performance index (PI). AS was defined as the highest pressure over the baseline that was successfully hold for 10 repetitions of 10-second period, and it was considered to show the strength of the deep flexor muscles of the cervical region. PI was calculated by multiplying the pressure increase from the baseline and the number of successful repetitions, and it was recorded as the endurance measurement of the deep flexor muscles. Failure was defined as a pressure loss of more than 2 mmHg of the goal. Both the AS (ICC $=$ 0.57; 95% CI 0.37, 0.72) and the PI (ICC $=$ 0.54; 95% CI 0.36, 0.70) showed good inter-rater reliability [31].

Figure 2.

Craniocervical flexion test levels’ progression.

NDI and The Fremantle Neck Awareness Questionnaire (FreNAQ-T) were used to evaluate functional status. NDI, which was one of our primary outcomes, was used to evaluate the level of disability that could occur due to neck pain. The questionnaire consists of 10 questions inquiring on pain intensity, personal care, lifting, reading, headaches, concentration, work, driving, sleeping, and recreation. High scores indicate a high degree of disability [32]. FreNAQ-T evaluates changes in individual-specific perception. The questionnaire evaluates neglect, proprioceptive sensation, and body shape-size perception and has 5 different response options that can be scored between 0 (never) and 4 (always). High scores indicate a low level of neck awareness [33].

In order to assess psychosocial status, the NeckPix Scale, Fear-Avoidance Beliefs Questionnaire (FABQ), Hospital Anxiety and Depression Scale (HADS) and Cognitive Exercise Therapy Approach-Biopsychosocial Questionnaire (BETY-BQ) were used. The NeckPix Scale was developed to assess kinesiophobia in individuals with chronic neck pain. Higher scores indicate greater fear of movement [34]. The Fear-Avoidance Beliefs Questionnaire (FABQ) was used to assess fear and avoidance beliefs. The questionnaire consists of 2 parts, namely physical activities (0–24) and work (0–42). A high total score indicates that the individual’s fear-avoidance behaviors are high [35]. HADS was used to evaluate anxiety (HADS-A) and depression (HADS-D) levels. High scores indicate higher levels of anxiety and depression [36]. BETY-BQ was used to evaluate the biopsychosocial status of the participants. BETY-BQ is a 30-item scale that includes multiple biopsychosocial components including improvement in pain coping skills, socialization, positive mood, sexuality, functionality, fatigue, and sleep quality. A higher score indicates a less favorable biopsychosocial status [37, 38].

Short Form-36 (SF-36) was used to evaluate the effects of neck pain on quality of life. It questions physical functioning (PF), social functioning (SF), role limitations due to physical complaints (PR), role limitations due to emotional problems (ER), mental health (MH), energy-vitality (V), bodily pain (BP), general health perception (GH), and changes in health. Higher scores indicate a higher quality of life [39].

VAS was used to determine the treatment satisfaction levels of the participants (0 $=$ very dissatisfied, 10 $=$ very satisfied). The satisfaction level of each participant was determined by recording the distance between the marked point and the starting point in cm.

After the assessments, a special session was organized for each participant to teach five main areas of focus (breath control, pelvic lumbar region, chest, shoulder, head, and neck positioning) and the basic principles of Pilates. After the participants successfully learned these, clinical Pilates exercises were taught while preserving key elements. Pilates was performed 3 days a week for 6 weeks and in groups consisting of 3 people each (Table 1).

Table 1.

Clinical Pilates exercise program

Warming phase (5 repetitions): • Roll down • Toy soldier • Upper extremity proprioceptive neuromuscular facilitation pattern (bilateral)
Exercise phase (10 repetitions)
First 3 weeks Hundreds 1 Swan dive 1 Double leg stretch 1 Swimming 1 Arm openings 1 Breaststroke preparations 1–2 Cobra Diamond press (with TheraBand) Roll up Spine twist (with TheraBand)	Second 3 weeks Hundreds 2 Swan dive 2 Double leg stretch 2 Swimming 2 Arm openings 2 Breaststroke Cobra Diamond press with arm openings (with TheraBand) Shoulder bridge 1 Side Bend (with TheraBand)
Cooling phase (5 repetitions): • Spine Stretch • Mermaid (bilateral) • Corkscrew

CT was carried out 3 days a week for 6 weeks. The CT program involved the implementation of 20 minutes of HP application, 20 minutes of conventional TENS applied to the painful area (80 Hertz (Hz), 100 microseconds ($\mu$s), until tingling is felt, asymmetrical biphasic rectangular waveform), and 8 minutes of US (4 minutes $+$ 4 minutes, 1.5 watts/cm², 1 MHz, continuous) to the cervical area.

2.1. Statistical analysis

The Statistical Package for the Social Sciences (SPSS) 26.0 software was used for the statistical analyses of the collected data. The distributions of the sociodemographic characteristics of the participants according to their groups were determined by frequency analysis, and the Pearson chi-squared test was used to compare the sociodemographic characteristics of the two groups. The conformity of the data of the participants in both groups to normal distribution was examined with the Shapiro-Wilk test, and it was determined that the data showed normal distribution. Levene’s Test was used to test for homogeneity of variances and it was found to be homogeneous. The independent-samples $t$-test method was used to compare the pre-intervention and post-intervention measurement values of the participants in both groups, and the paired-samples $t$-test method was used for intragroup comparisons. ANCOVA was used to compare the changes in the two groups. In addition to comparing the values before and after the intervention minimal clinically important differences (MCID) values were also calculated to reflect a clinically important difference from the patients’ perspective. MCID is the smallest change in an outcome measure resulting from a clinical intervention that is considered to have a meaningful and significant impact for the patient.

3. Results

Considering the sociodemographic and anthropometric characteristics of the groups, while there was a statistically significant difference between the groups in terms of age ( 0.05), it was seen that there was no significant difference in terms of their anthropometric characteristics ($p>$ 0.05) (Table 2).

Table 2.

Comparison of sociodemographic measurements of participants according to their groups

	Pilates ($n=$ 25)  $\overline{x}$$\pm$$s$	Pilates-CT ($n=$ 25)  $\overline{x}$$\pm$$s$	$t$	$P$
Age (years)	39.00 $\pm$ 10.02	45.56 $\pm$ 9.54		0.022*
Weight (kilogram)	62.00 $\pm$ 9.72	67.04 $\pm$ 11.65	$-$1.661	0.103
Height (centimeter)	162.08 $\pm$ 5.38	162.04 $\pm$ 8.22	0.020	0.984
Body mass index (kg/m2)	24.20 $\pm$ 4.48	25.70 $\pm$ 5.30	$-$1.084	0.284

0.05. $\overline{x}$$\pm$$s$: mean $\pm$ standard deviation, CT: Conventional treatment.

A statistically significant decrease was observed in the post-treatment pain intensity values of the participants in the morning, during rest, and during activity ( 0.05). The degree of change in pain intensity values during rest and activity in the Pilates-CT group was significantly higher than that in the Pilates group (Table 3).

Table 3.

Comparison of the pre-intervention and post-intervention pain scores of the participants

	Pre-intervention		$p$ 1	Post-intervention	$p$ 2	$p$ 3	MCID	$F$	$p$ 4	$\eta$ 2
	Group	$\overline{x}$ $\pm$ $s$		$\overline{x}$ $\pm$ $s$
VAS morning (cm)	Pilates	5.98 $\pm$ 2.28	0.290	2.49 $\pm$ 1.73	0.345	0.000*	7.06	0.985	0.326	0.021
	Pilates-CT	6.66 $\pm$ 2.21		2.02 $\pm$ 1.80		0.000*	7.60
VAS rest (cm)	Pilates	6.92 $\pm$ 2.26	0.661	4.02 $\pm$ 2.16	0.018*	0.000*	5.44	7.488	0.009*	0.137
	Pilates-CT	7.17 $\pm$ 1.66		2.48 $\pm$ 2.31		0.000*	7.88
VAS activity (cm)	Pilates	5.92 $\pm$ 3.27	0.414	3.33 $\pm$ 2.76	0.002*	0.000*	4.83	10.459	0.002*	0.182
	Pilates-CT	5.27 $\pm$ 2.19		1.32 $\pm$ 1.39		0.000*	8.48

^* 0.05. $p_1$: Pre-treatment intergroup comparison, $p_2$: Post-treatment intergroup comparison, $p_3$: Intragroup comparison, $p_4$: ANCOVA, MCID: minimal clinically important difference, ${\eta }^2$: Eta-squared (Effect size), $\overline{x}$$\pm$$s$: mean $\pm$ standard deviation, VAS: Visual Analog Scale, CT: Conventional treatment.

Statistically significant differences were observed in the pre-intervention and post-intervention flexion, extension, lateral flexion (right-left), and rotation (right-left) ROM, cervical flexor endurance, and extensor endurance test results, CCFT-AS scores, and CCFT-PI scores of the participants in the two groups ( 0.05). It was shown that the changes in the extension ROM and cervical flexor endurance values in the post-intervention of the Pilates-CT group were significantly higher than those in the Pilates group ( 0.05) (Table 4).

Table 4.

Comparison of the pre-intervention and post-intervention range of motion and cervical muscle endurance values of the participants

	Pre-intervention		$p$ 1	Post-intervention	$p$ 2	$p$ 3	MCID	$F$	$p$ 4	$\eta$ 2
	Group	$\overline{x}$ $\pm$ $s$		$\overline{x}$ $\pm$ $s$
Flexion ROM (∘)	Pilates	34.32 $\pm$ 8.20	0.236	41.20 $\pm$ 4.85	0.324	0.000*	$-$4.79	0.136	0.714	0.003
	Pilates-CT	36.80 $\pm$ 6.26		42.40 $\pm$ 3.57		0.000*	$-$6.24
Extension ROM (∘)	Pilates	26.40 $\pm$ 6.21	0.012*	28.60 $\pm$ 5.11	0.891	0.009*	$-$2.86	6.030	0.018*	0.114
	Pilates-CT	21.88 $\pm$ 5.97		28.40 $\pm$ 5.15		0.000*	$-$7.29
Right lateral flexion ROM (∘)	Pilates	30.80 $\pm$ 6.53	0.510	38.00 $\pm$ 3.82	0.173	0.000*	$-$5.84	1.469	0.231	0.030
	Pilates-CT	32.08 $\pm$ 7.09		39.40 $\pm$ 3.33		0.000**	$-$5.28
Left lateral flexion ROM (∘)	Pilates	34.32 $\pm$ 5.76	0.560	38.00 $\pm$ 3.82	0.173	0.008*	$-$2.90	2.667	0.109	0.054
	Pilates-CT	33.32 $\pm$ 6.26		39.40 $\pm$ 3.33		0.000*	$-$5.52
Right rotation ROM (∘)	Pilates	36.08 $\pm$ 9.17	0.014*	42.40 $\pm$ 5.23	0.161	0.000*	$-$4.16	0.004	0.947	0.000
	Pilates-CT	41.16 $\pm$ 3.99		44.00 $\pm$ 2.04		0.001*	$-$3.87
Left rotation ROM (∘)	Pilates	37.48 $\pm$ 7.56	0.031*	42.60 $\pm$ 4.59	0.170	0.000*	$-$4.12	0.009	0.923	0.000
	Pilates-CT	41.24 $\pm$ 3.85		44.00 $\pm$ 2.04		0.000*	$-$4.85
Cervical flexor endurance test (sec)	Pilates	42.39 $\pm$ 24.93	0.049*	65.84 $\pm$ 37.29	0.598	0.000*	$-$4.87	6.147	0.017*	0.116
	Pilates-CT	31.08 $\pm$ 12.87		70.57 $\pm$ 24.33		0.000*	$-$8.97
Cervical extensor endurance test (sec)	Pilates	70.07 $\pm$ 36.89	0.043*	106.24 $\pm$ 40.68	0.957	0.000*	$-$7.41	3.271	0.077	0.065
	Pilates-CT	52.26 $\pm$ 21.97		106.83 $\pm$ 36.76		0.000*	$-$8.10
Craniocervical flexion test- activation score	Pilates	7.12 $\pm$ 2.52	0.036*	10.00 $\pm$ 0.00	1.000	0.000*	$-$5.71	–	–	–
	Pilates-CT	5.20 $\pm$ 3.65		10.00 $\pm$ 0.00		0.000*	$-$6.57
Craniocervical flexion test-performance index	Pilates	57.68 $\pm$ 30.15	0.226	100.00 $\pm$ 0.00	1.000	0.000*	$-$7.02	–	–	–
	Pilates-CT	46.28 $\pm$ 35.41		100.00 $\pm$ 0.00		0.000*	$-$7.59

^* 0.05. $p_1$: Pre-treatment intergroup comparison, $p_2$: Post-treatment intergroup comparison, $p_3$: Intragroup comparison, $p_4$: ANCOVA, MCID: minimal clinically important difference, ${\eta }^2$: Eta-squared (Effect size), $\overline{x}$$\pm$$s$: mean $\pm$ standard deviation, CT: Conventional treatment, ^∘: degree, Sec: second, ROM: Range of motion.

The post-intervention NDI, FreNAQ-T, NeckPix Scale, and HADS-A scores of the participants in both groups were found to be significantly lower than their pre-intervention scores ( 0.05). Additionally, the participants in the Pilates-CT group had significantly lower pre-intervention and post-intervention FABQ physical activity and work subscale scores, HADS-D scores, and BETY-BQ scores compared to those in the Pilates group ( 0.05). It was shown that the degrees of change in the NDI, FreNAQ-T, NeckPix Scale, HADS-D, and BETY-BQ scores of the participants in the Pilates-CT group were significantly higher than the degrees of change in the scores of those in the Pilates group ( 0.05) (Table 5).

Table 5.

Comparison of the pre-intervention and post-intervention functional and psychosocial status measure scores of the participants

	Pre-intervention		$p$ 1	Post-intervention	$p$ 2	$p$ 3	MCID	$F$	$p$ 4	$\eta$ 2
	Group	$\overline{x}$ $\pm$ $s$		$\overline{x}$ $\pm$ $s$
Neck disability index (0–50)	Pilates	19.12 $\pm$ 4.79	0.794	13.40 $\pm$ 7.53	0.014*	0.000*	4.16	7.385	0.009*	0.136
	Pilates-CT	18.68 $\pm$ 6.87		8.52 $\pm$ 5.89		0.000*	8.08
FreNAQ-T	Pilates	9.92 $\pm$ 7.81	0.173	7.72 $\pm$ 7.65	0.368	0.034*	2.25	6.902	0.012*	0.128
	Pilates-CT	13.40 $\pm$ 9.87		5.96 $\pm$ 5.93		0.000*	5.05
NeckPix scale (0–100)	Pilates	54.68 $\pm$ 18.03	0.761	38.48 $\pm$ 21.53	0.017*	0.000*	4.33	10.086	0.003*	0.177
	Pilates-CT	56.36 $\pm$ 20.70		24.16 $\pm$ 19.44		0.000*	8.73
FABQ-physical activities (0–24)	Pilates	14.08 $\pm$ 6.92	0.554	11.16 $\pm$ 7.20	0.267	0.051	2.07	2.963	0.092	0.059
	Pilates-CT	15.24 $\pm$ 6.84		8.88 $\pm$ 7.17		0.000*	5.13
FABQ-work (0–42)	Pilates	21.88 $\pm$ 10.42	0.871	19.04 $\pm$ 11.64	0.241	0.118	1.62	2.337	0.133	0.047
	Pilates-CT	21.40 $\pm$ 10.37		15.28 $\pm$ 10.71		0.000*	4.15
HADS-Anxiety	Pilates	10.24 $\pm$ 5.43	0.357	8.04 $\pm$ 4.95	0.101	0.019*	2.52	1.869	0.178	0.038
	Pilates-CT	8.92 $\pm$ 4.58		5.96 $\pm$ 3.75		0.002*	3.45
HADS-Depression	Pilates	7.52 $\pm$ 4.14	0.279	6.72 $\pm$ 3.93	0.190	0.311	1.04	4.906	0.032*	0.095
	Pilates-CT	8.76 $\pm$ 3.85		5.36 $\pm$ 3.26		0.000*	4.84
BETY-BQ (0–120)	Pilates	46.72 $\pm$ 21.66	0.929	40.40 $\pm$ 22.34	0.017*	0.083	1.81	12.119	0.001*	0.205
	Pilates-CT	47.24 $\pm$ 19.52		27.04 $\pm$ 14.97		0.000*	7.41

^* 0.05. $p_1$: Pre-treatment intergroup comparison, $p_2$: Post-treatment intergroup comparison, $p_3$: Intragroup comparison, $p_4$: ANCOVA, MCID: minimal clinically important difference. ${\eta }^2$: Eta-squared (Effect size), $\overline{x}$$\pm$$s$: mean $\pm$ standard deviation, CT: Conventional treatment, FreNAQ-T: Fremantle Neck Awareness Questionnaire, FABQ: Fear-Avoidance Beliefs Questionnaire, HADS: Hospital Anxiety and Depression Scale, BETY-BQ: Cognitive Exercise Therapy Approach-Biopsychosocial Questionnaire.

It was determined that while there was no significant difference between the pre-intervention and post-intervention SF-36 energy/vitality and general health dimension scores of the participants in the Pilates group ($p>$ 0.05), their post-intervention scores in the physical functioning, role restrictions due to physical and emotional problems, mental health, social functioning, bodily pain dimensions were significantly higher than their pre-intervention scores ( 0.05). The post-intervention SF-36 subscale scores of the participants in the Pilates-CT group were found to be significantly higher than their pre-intervention scores ( 0.05). The degree of change in the SF-36 energy subscale scores of the participants in the Pilates-CT group was significantly higher than that in the Pilates group ( 0.05) (Table 6).

Table 6.

Comparison of the pre-intervention and post-intervention Short Form-36 parameter scores of the participants

	Pre-intervention		$p$ 1	Post-intervention	$p$ 2	$p$ 3	MCID	$F$	$p$ 4	$\eta$ 2
	Group	$\overline{x}$ $\pm$ $s$		$\overline{x}$ $\pm$ $s$
Physical functioning	Pilates	69.20 $\pm$ 15.52	0.272	77.00 $\pm$ 14.36	0.527	0.026*	$-$2.37	1.413	0.241	0.029
	Pilates-CT	63.60 $\pm$ 19.87		79.80 $\pm$ 16.61		0.000*	$-$4.15
Role limitations due to physical complaints	Pilates	28.00 $\pm$ 30.03	0.479	48.00 $\pm$ 37.44	0.057	0.012*	$-$2.72	3.219	0.079	0.064
	Pilates-CT	35.40 $\pm$ 42.28		70.00 $\pm$ 42.08		0.001*	$-$3.86
Role limitations due to emotional complaints	Pilates	41.33 $\pm$ 32.33	0.686	55.99 $\pm$ 32.95	0.182	0.013*	$-$2.68	1.627	0.208	0.033
	Pilates-CT	45.33 $\pm$ 37.13		67.99 $\pm$ 29.63		0.026*	$-$2.37
Energy/vitality	Pilates	42.24 $\pm$ 20.24	0.766	46.80 $\pm$ 16.45	0.051	0.159	$-$1.45	5.113	0.028*	0.098
	Pilates-CT	43.80 $\pm$ 16.35		57.20 $\pm$ 20.11		0.001*	$-$3.96
Mental health	Pilates	57.64 $\pm$ 20.50	0.283	64.80 $\pm$ 20.13	0.093	0.046*	$-$2.10	1.685	0.201	0.035
	Pilates-CT	63.04 $\pm$ 14.06		73.40 $\pm$ 14.98		0.002*	$-$3.53
Social functioning	Pilates	63.00 $\pm$ 18.21	0.793	72.72 $\pm$ 20.01	0.063	0.009*	$-$2.86	3.711	0.060	0.073
	Pilates-CT	64.50$\pm$21.85		82.50 $\pm$ 16.14		0.001*	$-$3.60
Bodily pain	Pilates	36.00 $\pm$ 24.13	0.708	54.30 $\pm$ 28.21	0.205	0.000*	$-$4.28	3.602	0.064	0.071
	Pilates-CT	33.82 $\pm$ 15.93		64.00 $\pm$ 25.10		0.000*	$-$7.00
General health perception	Pilates	50.20 $\pm$ 20.49	0.603	52.80 $\pm$ 21.80	0.070	0.355	$-$0.94	3.726	0.060	0.073
	Pilates-KT	53.00 $\pm$ 17.14		63.80 $\pm$ 20.17		0.013*	$-$2.67

^* 0.05. $p_1$: Pre-treatment intergroup comparison, $p_2$: Post-treatment intergroup comparison, $p_3$: Intragroup comparison, $p_4$: ANCOVA, MCID: minimal clinically important difference. ${\eta }^2$: Eta-squared (Effect size), $\overline{x}$$\pm$$s$: mean $\pm$ standard deviation, CT: Conventional treatment.

The results of the independent-samples $t$-test that was conducted to compare the treatment satisfaction scores of the participants between the groups are given in Table 5. Accordingly, the treatment satisfaction levels of the participants in the Pilates-CT group were significantly higher ( 0.05) (Table 7).

Table 7.

Comparison of the treatment satisfaction scores of the participants

	Group	$n$	$\overline{x}$ $\pm$ $s$	$T$	$P$
Treatment satisfaction (0–10) (cm)	Pilates	25	7.64 $\pm$ 1.78	$-$3.451	0.001*
	Pilates-CT	25	9.09 $\pm$ 1.11

^* 0.05. $\overline{x}$$\pm$$s$: mean $\pm$ standard deviation. CT: Conventional treatment.

4. Discussion

Our results showed that adding CT to clinical Pilates as an intervention was more effective in reducing pain, disability, fear of movement, depression levels, biopsychosocial involvement, extension ROM, cervical flexor endurance, neck awareness levels, parameters of energy/vitality in the context of quality of life, and treatment satisfaction compared to the intervention implemented with clinical Pilates alone. The high compliance with the treatment groups and the absence of dropouts may be attributed to satisfaction with the clinical Pilates treatment.

Although neuromuscular exercises, stretching, strengthening, flexibility exercises, and endurance training were recommended for the cervical/scapulothoracic regions in chronic neck pain caused by various reasons [40], Pilates, which includes some of these types of exercise, is not yet among prevalently adopted recommendations. Furthermore, recommendations about the use of TENS and US, which have often been included in treatment plans in clinical practice, are contradictory. While TENS and high-powered US were recommended for use in individuals with neck pain in the chronic period [40], other practice guidelines did not recommend electrotherapy and US because of the low quality of evidence [21]. HP, which is among the physical modalities frequently used in the clinic, was not among the thermal agents recommended for individuals with chronic neck pain [41].

Pilates performed for different durations (6–12 weeks) reduces pain levels in general, at rest, and during activity in individuals with chronic neck pain [42, 43, 44, 45, 46]. On the other hand, in another study in which mat Pilates was performed, while general pain levels did not change in the first 6 weeks, they decreased in the next 6-week follow-up period [25]. In another study, 15 sessions of CT (HP, TENS, and US) were applied in addition to Pilates, Yoga, and isometric exercises. Since the aim of the study was to compare the effectiveness of different types of exercise, the additional effect of CT was not investigated [47]. Although there have been methodological differences in different studies in the literature, Pilates has been seen to be an effective exercise approach in reducing pain levels in individuals with chronic neck pain in general.

In this study, the clinical Pilates program was formed to include the warm-up and cool-down phases, similar to the literature. The program, which was applied 3 days a week for 6 weeks, was advanced at the end of 3 weeks. Within the scope of the CT program, HP, TENS, and US were applied. Since there was no information on the effective use of HP, which has been frequently preferred in clinical practice, it was applied to the neck area for 20 minutes as used in the clinic. The physiological response of conventional TENS, which is one of the neuromodulation techniques whose mechanism of action is based on the “Gate Control Theory”, depends on the frequency and intensity of the treatment. In a Cochrane review, it was been reported that the frequency of TENS should be 60–100 Hz, its pulse width should be 40–250 $\mu$s, its intensity should be suitable for patient comfort, and the method should be applied on the most painful area for a duration of 20 to 60 minutes [48]. Therefore, in this study, we applied TENS at 80 Hz and 100 $\mu$s, with an asymmetric biphasic rectangular waveform on painful areas for 20 minutes until tingling was felt. US, which increases deep tissue temperatures by 2–3^∘C, was applied at 1 MHz, in the continuous mode, and at 1.5 W/cm², which has been frequently preferred in the treatment of chronic neck pain and shown to be effective on pain [17]. At the end of the study, it was observed that both groups had a significant decrease in pain intensity in the morning, at rest, and during activity. While no difference was found in the degrees of change in pain levels felt in the morning in the comparison between the groups, the degrees of change in pain intensity values during rest and activity among the participants in the Pilates-CT group were found to be significantly higher. In addition, the improvements obtained in our study were demonstrated by the VAS (morning, activity, rest) MCID values of both groups exceeding the MCID values determined in the literature (1.5–2.5 cm) [49]. It was determined that the MCID values of the Pilates-CT group were higher than those of the Pilates group. These results supported the results of other studies showing the effect of Pilates on pain levels at rest and during activity [45, 46], and they suggested that exercise should be supported with CT [17, 50]. CT probably supported reductions in pain intensities through thermal effects such as vasodilation, non-thermal effects such as micromassage, and “Gate Control Theory”.

Active ROM may decrease due to impaired mobility, pain, and increased muscle tone in individuals with neck pain [2, 51]. It was reported that ROM did not improve in individuals with chronic mechanical neck pain at the end of a progressive Pilates intervention applied for 12 weeks and at 6-week follow-up [46]. In chronic mechanical neck pain, when CT (HP, interference flow, and exercise) was applied in one group, and Pilates was applied in the other group in addition to CT for 3 months, a significant improvement in cervical ROM was noted in both groups [52]. However, it was not specified whether the goniometric measurement was active or passive. In another study, active joint movement increased as a result of the application of Pilates in addition to CT, which was similar to the CT used in this study, but it was not specified which ROM values were evaluated [47]. The exercise model we preferred in this study was the clinical Pilates method that targets postural alignment, balance between muscles, and spinal stabilization. Şahiner and Yeşilyaprak reported that Pilates improved normal joint ROM in all directions except for extension [42]. As a result of our study, it was seen that active flexion, extension, lateral flexion (right-left), and rotation (right-left) ROM increased in both groups, and in the comparison between the groups, CT in addition to Pilates was superior in increasing the normal ROM in the extension direction. These results may have been obtained due to the favorable effect of CT on pain levels, tissue extensibility, and muscle tone.

In the study by Nandita et al., which lasted for 12 weeks, CT (interferential current, HP, and exercise) was applied to the control group and Mat-Pilates to the experimental group in addition to CT without advancing the program, and it was reported that there was an increase in neck flexor endurance test results in both groups [52]. In another study, as a result of Mat-Pilates, which was applied 2 days a week for 6 weeks and advanced during the study, as evaluated using CCFT-PI (0–300), an increase in the endurance of the deep cervical flexor muscles was detected [42]. In the results of our study, it was seen that the cervical flexor and extensor endurance values of both groups and the strength and endurance of the deep cervical flexors increased, similar to other studies in the literature. It was determined that CT in addition to Pilates was more effective in increasing cervical flexor endurance. However, since both groups reached the maximum AS of 10 repetitions in CCFT and the maximum PI of 100 seconds, a comparison between the groups could not be made. The application of CT in addition to Pilates may have led to a greater reduction in pain levels during rest and activity, resulting in an improvement in motor control, as well as an increase in deep muscle activity, that is, cervical flexor endurance, by reducing superficial muscle activity.

When CT was combined with Pilates, it provided more effective improvements in neck disability compared to other techniques [47, 52]. Long-term training and repetition are needed to intuitively use the motor control learned in Pilates during activities of daily living. In this study, although Pilates practiced 3 days a week for 6 weeks significantly reduced disability levels, it was determined that CT in addition to Pilates was more successful in improving functional status. In addition to pre- and post-intervention comparisons, the MCID value for the NDI was also determined. While the average NDI change in the Pilates-CT group (8.08) exceeded the minimal clinically important difference (MCID) value (7.5) reported by Young et al., it was determined that although there was an improvement in the NDI value in the Pilates group, it did not reach the MCID [53]. We thought that our results, which were in parallel with the results of other studies in the literature [47, 52], were a consequence of the fact that CT in addition to Pilates was more effective in decreasing pain and increasing ROM, and neck flexor muscle endurance.

Contemporary theories of pain suggest that how the body is perceived plays a central role in the manifestation of pain. Additionally, it was argued that neck awareness is associated with factors such as pain, disability, anxiety, and quality of life [33]. The Pilates method is an exercise method that supports the provision of postural alignment by targeting body and posture awareness [54]. In the literature review, no study investigating the effects of Pilates on neck awareness in individuals with chronic neck pain could be found. In this study, it was found that neck awareness significantly improved in both groups, and Pilates supported by CT was more effective in improving neck awareness. Raizah et al. reported that cervical proprioception was impaired in individuals with chronic neck pain compared to asymptomatic individuals [55]. Although we did not evaluate neck proprioception in our study, our prediction is that there may be an increase in proprioception in the Pilates-Ct group, with postural alignment and additional analgesic effect, and this may be reflected in postural awareness.

In individuals with chronic neck pain, kinesiophobia is significantly associated with pain intensity and functional performance [56]. After the interventions in our study, kinesiophobia levels decreased in both groups, similar to the results reported by Akodu et al. [44], while CT provided in addition to Pilates was more effective in reducing kinesiophobia levels. Clinical Pilates can increase confidence in exercise by providing stabilization and motor control, preventing re-injury, and reducing pain levels during activities of daily living. In this study, the fact that the CT intervention provided in addition to Pilates resulted in a greater reduction in pain levels during activity increased functional status by further reducing kinesiophobia levels. It was determined that fear-avoidance beliefs decreased only in the intervention with CT in addition to Pilates, but no significant difference was observed in the comparison between the two groups. Although the short duration of our study, which was 6 weeks, was sufficient for reducing pain and fear of movement, interventions implemented for longer periods or cognitive exercise therapy approach might be needed to change fear-avoidance beliefs.

Psychological factors such as anxiety and depression are frequently observed in chronic pain cases. In individuals with chronic neck pain, especially pain levels were associated with anxiety [57]. CT provided in addition to Pilates was shown to be effective in reducing depression levels, but the effectiveness of Pilates performed alone or its effect on anxiety levels has not been investigated [47]. In this study, there was a decrease in the anxiety levels of both groups, but there was no significant difference between the two groups. In terms of the depression levels of the participants, it was observed that the CT given in addition to Pilates was more effective. Focusing on movement and diverting attention from pain during Pilates, as well as the improvement of functional status by reducing chronic pain, may have been effective in the changes in moods.

As in other chronic musculoskeletal disorders, biological factors (decreased muscle strength and endurance, postural misalignment, and pain levels), psychological factors (depressive mood, decreased ability to cope with pain, and kinesiophobia), and social factors play a role in the development of chronic neck pain. A holistic evaluation and treatment program is important in the management of chronic pain, since only recommending biomedical treatment for the individual may result in inadequate recovery. To the best of the author’s knowledge, there is no other study investigating the effects of Pilates on biopsychosocial status in individuals with chronic neck pain. In this study, it was observed that Pilates performed together with CT improved the biopsychosocial statuses of the participants. This improvement may have resulted from superior improvements in factors determining biopsychosocial status (pain, strength, endurance, function, and depression) seen in the Pilates-CT group.

Quality of life is also affected in individuals with chronic neck pain due to biopsychosocial factors. It was stated that while Pilates provides improvements in terms of sleep, physical activity, energy levels, pain parameters, and total quality of life scores, it does not cause any significant change in emotional reaction and social isolation parameters [47]. In another study, it was observed that Pilates, applied in addition to pharmacological treatment, provided improvements in all parameters except for the physical and emotional role dimensions of quality of life [43]. No study investigating the effects of Pilates alone on the quality of life of individuals with chronic neck pain was encountered. It was asserted that to improve pain levels, muscle weakness, and quality of life in individuals with chronic neck pain, an exercise program should be applied 3 times a week [57]. Therefore, in this study, the treatment was applied 3 days a week for 6 weeks, and it was determined that while the participants in both groups improved in terms of their physical function, role restrictions due to physical and emotional problems, mental health, social function, and pain, the participants in the Pilates-CT group also improved in terms of their energy and general health parameters. In the comparisons of the two groups, it was seen that Pilates supported with CT caused a greater increase in SF-36 energy subscale scores.

In chronic neck pain, patient satisfaction was associated with disability levels [58]. In this study, it was found that the participants in the Pilates-CT group had higher levels of treatment satisfaction. In the same group, treatment satisfaction may have increased due to superior improvements in other factors, especially in functional status. Compliance with the treatments in both groups and the absence of dropouts were also indicators of satisfaction with the Pilates exercises, which are considered mind-body exercises.

The increase in treatment satisfaction and full compliance during the study showed that the Pilates method used in this study was a safe exercise model that could increase adherence to treatment. We thought that after the completion of the CT provided in addition to Pilates in the clinic in individuals with chronic neck pain, the treatment can be continued with Pilates exercises, so that the treatment effects can be sustained for a longer time. However, future studies are needed to determine long-term effects.

One limitation of this study was the impossibility of blinding the patients and physical therapists, which is not feasible in exercise clinical trials. Another limitation was the short application time in CCFT in this current study. Individuals who met the inclusion and exclusion criteria were directed to the study by physicians. For this reason, imaging reports of the individuals such as magnetic resonance and X-ray were not recorded. This constituted another limitation of our study.

5. Conclusion

In women with chronic neck pain, adding CT (HP, TENS, and US) to clinical Pilates exercises was more effective in reducing pain levels, fear of movement, and depression and increasing neck extension ROM, flexor muscle endurance, functional status, neck awareness, and scores in the energy parameter of quality of life. These results suggested that CT in addition to Pilates is superior to Pilates alone in improving biopsychosocial status among patients with chronic neck pain. For more effective treatment of individuals with chronic neck pain in a short time, it is recommended to support active treatments (eg: Pilates exercises) with passive physiotherapy modalities. Our study was continued for 6 weeks, which is the minimum sufficient time for exercise effects to occur. However, the effects of both treatment modalities in the long term are not known, therefore, longer follow-up is recommended in future studies. Also, future studies should investigate the effects of Pilates-CT and Pilates in more homogeneous groups (e.g. cervical disc herniation) by adding a Pilates-sham CT group.

Conflict of interest

The authors declare that they have no conflict of interest.

Funding

The authors report no funding.