Effects of an Integrated Approach of Hatha Yoga Therapy on Functional Disability,Pain,and Flexibility in Osteoarthritis of the Knee Joint: A Randomized Controlled Study

Abstract

Objectives:

The study objectives were to evaluate the efficacy of integrating hatha yoga therapy with therapeutic exercises for osteoarthritis (OA) of the knee joints.

Design:

This was a prospective, randomized, active controlled trial. Two hundred and fifty (250) participants who had OA knees and who were between 35 and 80 years (yoga 59.56±9.54) and (control 59.42±10.66) from the outpatient department of Ebnezar Orthopedic Center, Bengaluru, were randomly assigned to receive hatha yoga therapy or therapeutic exercises after transcutaneous electrical stimulation and ultrasound treatment (20 minutes per day). Both of the groups practiced supervised interventions (40 minutes per day) for 3 months. One hundred and eighteen (118) (yoga) and 117 (control) subjects were available for the final analysis.

Results:

There were significant differences within (Wilcoxon's, p<0.001) and between the groups (Mann–Whitney U, p<0.001) on all the variables, with better improvements in the yoga than the control groups. Walking pain in the yoga (37.3%, 64.9%) and control (24.9%, 42%), knee disability in the yoga (59.7%, 83%) and control (32.7%, 53.6%), range of knee flexion in yoga (12.7%, 26.5% right, 13.5%, 28% left) and control (6.9%, 13.3% right, 5.6%, 11.5% left), joint tenderness in yoga (52.3%, 86.1%) and control (28%, 57.1%), swelling in yoga (55.4%, 85.9%) and control (32.1%, 60%), crepitus in yoga (44.0%, 79.9%) and control (27.0%, 47.8%) and walking time in yoga (26.6%, 52.8%) and control (9.3%, 21.6%), all improved more in the yoga than the control groups on the 15th and 90th day, respectively.

Conclusions:

An integrated approach of hatha yoga therapy is better than therapeutic exercises as an adjunct to transcutaneous electrical stimulation and ultrasound treatment in improving walking pain, range of knee flexion, walking time, tenderness, swelling, crepitus, and knee disability in patients with OA knees.

Introduction

O steoarthritis (OA) is the most common type of arthritis and is characterized primarily by articular cartilage degeneration and a secondary peri-articular bone response.^1,2 Worldwide, the prevalence rate of OA is 20% for men and 41% for women and it causes pain or dysfunction in 20% of the elderly.³ In India, OA is the second most common rheumatological problem and has a prevalence rate of 22%–39%.⁴ Relieving pain and stiffness, and improving physical function are the important goals of present-day therapy.^5,6 Nonopioid analgesics and anti-inflammatory drugs, which form the mainstay of drug treatment, do reduce pain and inflammation but their long-term use is associated with many adverse effects.^7,8

The need for safer treatment of OA has led to research into many alternative and complementary therapies.⁹ There are several randomized placebo-controlled trials (RCTs) that have used nonpharmacological interventions for OA knees. In a meta-analysis of 36 RCTs on 1391 patients, manual acupuncture, static magnets, and ultrasound therapies did not offer statistically significant short-term pain relief over placebo, while pulsed electromagnetic fields offered a small reduction in pain. Transcutaneous electrical nerve stimulation (including interferential currents), electro-acupuncture and low-level laser therapy offered clinically relevant pain relieving effects that seemed to persist for at least 4 weeks. This review by Bjordal et al. concluded that physiotherapy modalities at the most offer only short-term relief of pain and hence add-on therapies such as exercises, acupuncture, and so on may be beneficial.¹⁰

The beneficial effects of yoga on OA hands have been reviewed by Garfinkel.¹¹ This author studied the effects of 10 weeks of supervised yoga in an RCT on 25 subjects and showed significant reduction in pain, tenderness, and improved range of motion of fingers.¹² In another pilot study on 11 patients with OA knees, Kolasinski et al. showed reduction in pain and disability.¹³

Ranjita and Nagarathna (unpublished observations) showed 28%–45% improvement in pain and mobility after 1 week of intensive residential integrated yoga therapy for OA knees.

There are studies on add-on exercise to physiotherapy,¹⁴ and acupuncture to physiotherapy as adjuvant therapies,¹⁵ but there are no studies on add-on yoga to physiotherapy. Also, there are no RCTs that have looked at the effect of yoga on OA knees with active intervention for the control group. Hence, the present study was planned to study the effects of yoga as an adjunct to physiotherapy in the treatment of OA knees.

Materials and Methods

Two hundred and fifty (250) patients with OA knees from the outpatient department of Ebnezar Orthopedic Center, Bengaluru were recruited for the study. Table 1 shows the baseline characteristics that were similar between groups on all variables (p>0.05, Mann–Whitney test for prevalues). A sample size of 250 was obtained on G power software by fixing the α at 0.05 powered at 0.8 and an effect size of 0.379, considering the mean and SD of an earlier study.¹⁶

Table 1.

Demographic Data

Characteristics		Yoga (N=125)	Control (N=125)
Age (M±SD)		59.56±8.18	59.42±10.66
Sex	Males	37	39
	Females	88	86
Occupation	Skilled workers	28	32
	Semiskilled workers	34	31
	Unskilled workers	3	5
	Others	60	57
Duration of the disease	<1 yr	62	59
	1–2 yrs	39	40
	>2 yrs	24	26
Associated diseases
Diabetes		22	16
Hypertension		30	19
Overweight/obesity		98	73
Osteoporosis		78	67
Others		26	30

SD, standard deviation.

Two hundred and fifty (250) patients of both genders in the age group of 35–80 years (59.56±8.18) in the yoga group and (59.42±10.66) in the control group with OA knees (one or both joints) satisfying the American College of Rheumatism (ACR) guidelines¹⁷ for diagnosis were included. The inclusion criterions were (1) persistent pain for 3 months prior to recruitment; (2) moderate to severe pain on walking; (3) Kellgren and Lawrence¹⁸ radiologic grading of II–IV in x-ray films taken within 6 months prior to entry; and (4) those fully ambulant, literate, and willing to participate in the study. Those with (1) grade I changes in the x-ray films; (2) acute knee pain; (3) secondary OA due to rheumatoid arthritis, gout, septic arthritis, tuberculosis, tumor, trauma, or hemophilia; and (4) those with major medical or psychiatric disorders were excluded.

The study was approved by the Institutional Review Board and ethical committee of SVAYSA University. Signed informed consent was obtained from all the participants.

Design

This was a prospective, randomized, parallel active controlled study on patients with OA knees in the age range of 35–80 years. Patients attending the outpatient department of Ebnezar Orthopedic Center who satisfied the inclusion criteria were recruited for the study. After the initial screening for selection criteria, they were assigned to either the yoga or the control group. A computer-generated random-number table (www.randomization.com) was used for randomization. Numbered envelopes were used to conceal the sequence until the intervention was assigned. Both groups were given conventional physiotherapy using transcutaneous electrical stimulation and ultrasound for 2 weeks.

Both of the groups had supervised practices at the center (40 minutes per day) after physiotherapy (20 minutes per day) for 2 weeks. The yoga classes were conducted in the basement of the center where one hall was exclusively dedicated for yoga therapy. The study group was taught integrated yoga and the control group the nonyogic therapeutic exercises by certified therapists Dr. Yogitha Bali, Mrs. Pragati, and Mr. Rangaji—all trained at Yoga University, SVYASA, Bangalore. After this they were asked to practice daily at home for the next 12 weeks. The patients were asked to mark the practices daily in the diary provided for this purpose after their home practice. Compliance was supervised by telephone calls once in 3 days, and a weekly review was conducted once a week for 12 weeks. The daily review cards were checked for the regularity and doubts, if any, were clarified. This along with their clinical progress was checked and documented at every visit. All the assessments were carried out on the first, 15th, and 90th day by the therapists.

Blinding and masking

As this was an interventional study, double blinding was not possible. The answer sheets of the questionnaires were coded and analyzed after the study was completed. The statistician who did the randomization and data analysis, and the researcher who carried out the assessments were blinded to the treatment status of the subjects.

Intervention for yoga group

The daily routine practiced at the center in the yoga group included 40 minutes of integrated yoga therapy practice after 20 minutes of physiotherapy with transcutaneous electrical stimulation and ultrasound for 2 weeks. The integrated yoga therapy practice included shithilikarana vyayamas (loosening practices), sakti vikasaka (strengthening practices), followed by yogasanas and relaxation techniques with devotional songs. Later patients were advised to continue the integrated yoga therapy practice for 40 minutes at home for the next 10 weeks (Table 2).

Table 2.

Yoga Module for Osteoarthritic Knees

	Conventional physiotherapy: Was carried out only at the center for 15 days and included		20.0 min
	• TENS, 10 min
	• Ultrasound, 10 min
	Integrated yoga practice: The patient practiced at the center for 40 min for 15 days after the conventional physiotherapy and was later advised to continue at home for the next 3 months. This included the following practices:		40.0 min
	Shithilikarana vyayama (loosening exercises):		10.0 min
1.	Foot and ankle loosening practices
	➢ Passive rotation of each toe (clockwise and counterclockwise)	10 rounds	1.0 min
	➢ Toe bending	10 rounds	0.5 min
	➢ Passive rotation of ankle (clockwise and counterclockwise)	10 rounds	0.5 min
	➢ Ankle bending	10 rounds	0.5 min
	➢ Ankle rotation (clockwise and counterclockwise)	10 rounds	0.5 min
2.	Knee loosening practices
	➢ Bending the knee in prone position		1.0 min
	➢ Knee bending – both sides	10 rounds	0.5 min
	➢ Knee rotation – both sides	10 rounds	0.5 min
	➢ Passive patella rotation		0.5 min
3.	Hip and waist loosening practices
	➢ Half butterfly	10 rounds	0.5 Min
	➢ Full butterfly	10 rounds	0.5 Min
	➢ Hip rotations (both internal and external)	10 rounds	0.5 min
4.	Upper limbs loosening practices
	➢ Finger loosening	10 rounds	0.5 Min
	➢ Wrist loosening	10rounds	0.5 Min
	➢ Wrist rotation (clockwise and counterclockwise)	10 rounds	0.5 min
5.	Neck loosening practices
	➢ Forward and backward bending	10 rounds	1.0 min
	➢ Neck rotation (both clockwise and counterclockwise )	10 rounds	0.5 min
6.	Relaxation: instant		2.0 min
7.	Strengthening exercises ( sakti vikaasaka suksma vyayama )		5.0 min
	➢ Back exercises (kati sakti vikaasaka)	5 rounds	0.5 min
	➢ Thigh exercises (jangha sakti vikaasaka)	5 rounds	0.5 min
	➢ Straight leg-raise breathing: single and both legs	10 rounds	1.5 min
	➢ Knee cap tightening: single and both legs	10 rounds	2.0 min
	➢ Ankle-tightening exercises	5 rounds	0.5 min
8.	Quick relaxation technique: Consists of three phases involving observing the abdominal movements, synchronizing them with breathing, and chanting of “A” kara, wherein “A” is the mantra.		3.0 min
9.	Yogasanas		10.0 min
	A. Standing asanas
	➢ Tadasana
	➢ Ardha kati chakrasana
	➢ Ardha chakrasana
	➢ Prasarita padahastasana
	B. Lying asanas
	➢ Bhujangasana
	➢ Shalabasana
	➢ Viparita karani
10.	Deep relaxation technique: Is a three-phase guided relaxation technique with relaxation from toes to the head, feeling of letting go, chanting OM, and feeling of limitless expansion through visualization.		5.0 min
11.	Nadi Shudi Pranayama : Nadi shudhi pranayama is a slow rhythmic technique of alternate nostril breathing involving the phases of inhalation and exhalation using nasika mudra.		3.0 min
12.	OM meditation: Is done seated in any comfortable meditative posture and repeating the syllable OM mentally.		2.0 min

TENS, transcutaneous electrical nerve stimulation.

The concepts used to develop a specific module of an integrated approach of yoga therapy for knee pain were taken from the traditional yoga scriptures (patanjali yoga sutras, yoga vasishtha, and upanishads) that highlight a holistic lifestyle for positive health at physical, mental, emotional, and intellectual levels.¹⁹ Yoga is defined as the mastery over the modifications of mind (chitta vritti nirodhah: definition of yoga by patanjali). It helps to remove the unnecessary surges of neuromuscular activation resulting from heightened stress responses that may contribute to aging.²⁰ The daily routine included a 40 minutes practice as follows:

• Yogic sukshma vyayamas (loosening and strengthening practices): These are safe, rhythmic, repetitive stretching movements synchronized with breathing. These practices mobilize the joints and strengthen the peri-articular muscles.

• Relaxation techniques: Three (3) types of guided relaxation techniques were interspersed between the physical practices of sukshmavyayamas and asanas.

• Asanas (physical postures): Asanas are characterized by effortless maintenance in the final posture by internal awareness. Asanas were selected in standing, supine, and prone positions that would relax and strengthen the knee joints.

• Pranayama: The practice of voluntary regulated breathing while the mind is directed to the flow of breath is called pranayama. These practices promote autonomic balance through mastery over the mind.²¹

• Meditation: Patanjali defines meditation (dhyana) as effortless flow of a single thought in the mind without distractions (pratyaya ekataanata dhyanam). This has been shown to offer physiologic benefits through alertful rest to the mind–body complex.²²

• Lectures and counseling: Yogic concepts of health and disease, yama, niyama, bhakti yoga, jnana yoga, and karma yoga were presented in the theory classes. These sessions were aimed at understanding the need for lifestyle change, weight management, and preventing early aging by yogic self-management of psychosocial stresses.

Intervention for control group

The daily routine practiced at the center in the control group included 40 minutes of therapeutic exercises after 20 minutes of physiotherapy with transcutaneous electrical stimulation and ultrasound for 2 weeks. These therapeutic exercises included loosening and strengthening practices for all the joints of the upper and lower limbs, a brief period of rest, specific knee practices, and supine rest followed by light music. Later the patient was advised to continue the therapeutic exercise practice of 40 minutes at home for the next 12 weeks (Table 3).

Table 3.

Control Module for Osteoarthritic Knees

	Conventional physiotherapy: was carried out only at the center for 15 days and included		20.0 min
	• TENS: 10 min
	• Ultrasound: 10 min
	Therapeutic practices: The patient practiced at the center for 40 min for 15 days after the conventional physiotherapy and later was advised to continue at home for the next 3 months. This included the following practices:		40.0 min
	Loosening exercises		10 min
1.	Foot and ankle
	➢ Passive rotation of the toes (each toe clockwise and counterclockwise)	10 rounds	0.5 min
	➢ Passive rotation of the ankle (both clockwise and counterclockwise)	10 rounds	0.5 min
	➢ Toe bending	10 rounds	0.5 min
	➢ Ankle bending	10 rounds	0.5 min
	➢ Ankle rotation (clockwise and counterclockwise both sides)	10 rounds	0.5 min
2.	Knee
	➢ Knee bending: both sides	10 rounds	0.5 min
	➢ Knee rotation: both sides	10 rounds	0.5 min
3.	Hip and waist loosening practices
	➢ Half butterfly	10 rounds	0.6 min
	➢ Full butterfly	10 rounds	0.6 min
	➢ Hip rotations (both internal and external)	10 rounds	0.5 min
4.	Upper limbs loosening practices
	➢ Finger loosening	10rounds	0.6 min
	➢ Wrist loosening	10rounds	0.6 min
	➢ Wrist rotation (both clockwise and counterclockwise)	10 rounds	0.5 min
	➢ Elbow loosening	5 rounds	0.5 min
	➢ Arm loosening: forward and backward movements	10 rounds	0.5 min
5.	Neck loosening practices
	➢ Forward and backward bending	10 rounds	0.5 min
	➢ Sideward bending	10 rounds	0.5 min
	➢ Sideward tilting	5 rounds	0.5 min
	➢ Neck rotation (both clockwise and counterclockwise )	5 rounds	0.5 min
6.	Quick pause		2.0 min
7.	Strengthening exercises		5.0 min
	➢ Palm exercises	5 rounds	0.5 min
	➢ Elbow exercises	10 rounds	0.5 min
	➢ Arm exercises	5 rounds	0.5 min
	➢ Back exercises	5 rounds	0.5 min
	➢ Thigh exercises	5 rounds	0.5 min
	➢ Calf exercises	5 rounds	0.5 min
8.	Rest		3 min
9.	Specific knee practices		15.0 min
	➢ Flexion and extension with and without resistance		3 min
	➢ Knee cap tightening: self and against small pillow		3 min
	➢ Straight leg raising—single and both—30/60/90 degrees		5 min
	➢ Cycling		4 min
10.	Supine rest		5.0 min

Outcome variables

Pain while walking

Patients were asked to mark the severity of their pain experienced while walking in the past few days on the walking numerical rating scale (WNRS). For this purpose, a 10-cm line drawn in the center of a white sheet with “0” as “no pain” and “10” as “worst possible pain” was used.²³ Separate sheets were used during each assessment.

Knee disability score

This was assessed by WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index Score for Knee Joint) that consists of 24 questions under three domains as follows: Pain (5 questions), Physical functions (17 questions), and Stiffness (2 questions). Each item was scored by the patient on a 5-point scale (0–4). Total WOMAC score is the sum of the scores on all items. The higher the score, the more severe the disability is. This multidimensional questionnaire has well-defined reliability, test–retest reliability, content and construct validity, at Cronbach's α of 0.88–0.95 and concordance correlation coefficient of 0.85–0.94.²⁴

Active range of movements

The degree of knee flexion was measured by using a dial-type goniometer (Anand Agencies, Pune, India). This instrument has a dial with calibration from 0 to 360°. The patient rested in the supine position on the couch. The center of the goniometer was placed on the outer side of the knee joint with the two arms firmly held along the thigh and leg. The range of flexion was noted on the dial as the knee was bent slowly to its maximum.

Tenderness

Knee tenderness was graded by the clinician using the following key: Grade 1–tenderness on deep palpation, Grade 2–patient winces on pressure, Grade 3–patient winces and withdraws, and Grade 4–patient does not allow the examiner to touch.²⁵

Swelling of the knee

Swelling was graded on a 4 (0–3)-point scale by the clinician.

Crepitus

This was also assessed by the clinician on a 5-point severity scale (0–4).

Walking time

The time taken to walk 50 m was recorded using a stopwatch.

Statistical methods

The data were analyzed using SPSS Version 16. The baseline values of the two groups were checked for normal distribution by the Shapiro Wilk test. Baseline matching was checked by the Mann–Whitney test. Wilcoxon signed-rank test and Mann–Whitney U test were used for assessing “within” and “between” group differences, respectively.

Results

The study profile is shown in Figure 1. There were 7 dropouts in the study group and 8 in the control group. Table 4 shows the results within the yoga group on the 15th and 90th day. Table 5 shows the results within the control group on the 15th and 90th day. Table 6 shows the results between the yoga and control groups.

FIG. 1.

Study profile.

Table 4.

Comparison of Results Within Yoga Group

Yoga group
				95% CI
	VB	Pre & post	Mean±SD	LB	UB	ES	p-Value	% Change
1.	WP	Pre	9.54±0.60	9.43	9.65	3.69
		Po 1	5.98±0.92	5.81	6.15	5.82	<0.001	37.31
		Po 2	3.35±0.99	3.17	3.53	3.83	<0.001	64.88
2.	KDS	Pre	57.26±10.40	55.35	59.16	3.80
		Po 1	23.10±8.49	21.55	24.65	4.69	<0.001	59.65
		Po 2	9.72±4.87	8.83	10.61	2.35	<0.001	83.02
3.	RNF	Pre	89.40±11.06	87.20	91.60	1.82
		Po 1	100.76±10.96	98.59	102.93	2.03	<0.001	12.70
		Po 2	113.07±10.37	111.0	115.13	1.89	<0.001	26.47
4.	LNF	Pre	87.91±11.88	85.45	90.37	1.68
		Po 1	99.77±11.09	97.47	102.07	1.66	<0.001	13.49
		Po 2	112.53±10.26	110.41	114.66	1.52	<0.001	28.00
5.	TN	Pre	3.55±0.58	3.44	3.65	3.31
		Po 1	1.69±0.72	1.56	1.83	4.83	<0.001	52.39
		Po 2	0.49±0.63	0.37	0.60	2.41	<0.001	86.19
6.	SW	Pre	2.83±0.76	2.68	2.97	2.38
		Po 1	1.26±0.87	1.09	1.42	3.20	<0.001	55.47
		Po 2	0.40±0.57	0.29	0.51	1.38	<0.001	85.86
7.	CR	Pre	3.38±0.61	3.27	3.49	2.88
		Po 1	1.89±0.82	1.74	2.04	3.64	<0.001	44.08
		Po 2	0.68±0.85	0.52	0.83	2.03	<0.001	79.88
8.	WT	Pre	45.29±8.98	43.65	46.93	4.02
		Po 1	33.25±8.26	31.74	34.75	5.27	<0.001	26.58
		Po 2	21.37±8.13	19.88	22.85	5.66	<0.001	52.81

VB, variables; SD, standard deviation; CI, confidence interval; ES, effect size; % change; percentage change.WP, walking pain; KDS, knee disability score; RNF, right knee flexion; LNF, left knee flexion; TN, tenderness; SW, swelling; CR, crepitus; WT, walking time; Po 1, post (15th day); Po 2, post (90th day); LB, lower bound; UB, upper bound.

Table 5.

Comparison of Results Within Control Group

Control group
				95% CI
	VB	Pre & post	Mean±SD	LB	UB	ES	p-Value	%Change
1.	WP	Pre	9.29±0.73	9.16	9.42	2.38
		Po 1	6.98±1.09	6.78	7.18	2.78	<0.001	24.86
		Po 2	5.35±1.49	5.08	5.62	2.14	<0.001	41.98
2.	KDS	Pre	59.61±11.3	57.52	61.70	1.81
		Po1	42.74±13.67	40.21	45.26	2.33	<0.001	32.68
		Po 2	27.66±13.78	25.12	30.20	2.11	<0.001	53.59
3.	RNF	Pre	88.73±10.66	86.55	90.90	1.80
		Po1	94.79±10.71	92.61	96.97	1.89	<0.001	6.82
		Po 2	100.46±10.9	98.24	102.69	1.68	<0.001	13.21
4.	LNF	Pre	88.94±9.94	86.90	90.97	1.80
		Po 1	94.06±10.0	92.01	96.11	1.89	<0.001	5.75
		Po 2	99.15±9.91	97.12	101.18	1.82	<0.001	11.47
5.	TN	Pre	3.36±0.70	3.2266	3.48	2.83
		Po 1	2.42±0.66	2.29	2.53	3.92	<0.001	27.97
		Po 2	1.44±0.69	1.31	1.57	3.95	<0.001	57.14
6.	SW	Pre	2.80±0.78	2.65	2.94	2.28
		Po 1	1.90±0.81	1.74	2.04	2.80	<0.001	32.14
		Po 2	1.12±0.82	0.96	1.27	1.76	0.001	60
7.	CR	Pre	3.33±0.73	3.19	3.46	2.06
		Po 1	2.43±0.81	2.27	2.57	2.23	<0.001	27.02
		Po 2	1.74±1.00	1.55	1.92	1.32	<0.001	47.74
8.	WT	Pre	45.45±10.68	43.47	47.43	2.16
		Po 1	41.21±10.38	39.28	43.13	3.00	<.0.001	9.32
		Po 2	35.66±10.11	33.79	37.52	2.85	<0.001	21.54

VB, variables; SD, standard deviation; CI, confidence interval; ES, effect size; % change, percentage change; LB, lower bound; UB, upper bound; WP, walking pain; KDS, knee disability score; RNF, right knee flexion; LNF, left knee flexion; TN, tenderness; SW, swelling; CR, crepitus; WT, walking time; Po 1, post (15th day); Po 2, post (90th day).

Table 6.

Comparison of Results Between Groups

Between groups
	Variables	Pre & post	ES	p-Value
1.	WP	Pre		0.024
		Po 1	0.99	<0.001
		Po 2	1.58	<0.001
2.	KDS	Pre		0.25
		Po 1	1.73	<0.001
		Po 2	1.75	<0.001
3.	RNF	Pre		2.57
		Po 1	0.23	<0.001
		Po 2	0.68	<0.001
4.	LNF	Pre		0.32
		Po 1	0.31	<0.001
		Po 2	0.78	<0.001
5.	TN	Pre		0.14
		Po 1	1.06	<0.001
		Po 2	1.43	<0.001
6.	SW	Pre		2.22
		Po 1	0.76	<0.001
		Po 2	1.02	<0.001
7.	CR	Pre		2.46
		Po 1	0.66	<0.001
		Po 2	1.14	<0.001
8.	WT	Pre		2.72
		Po 1	0.85	0.001
		Po 2	1.52	0.001

ES, effect size; WP, walking pain; KDS, knee disability score; RNF, right knee flexion; LNF, left knee flexion; TN, tenderness; SW, swelling; CR, crepitus; WT, walking time; Po 1, post (15th day); Po 2, post (90th day).

Walking pain

The baselines were matched for both groups and data were not normally distributed. There was a significant difference in walking pain (WNRS) within (Wilcoxon, p<0.001) and between the groups (Mann–Whitney U test, p<0.001) after the intervention with higher effect size in the yoga than in the control group.

Knee disability score (WOMAC)

There was a significant difference in knee disability within (Wilcoxon, p<0.001) and between the groups (Mann–Whitney U test, p<0.001) after the intervention with higher effect size in the yoga than in the control group.

Goniometry for knee movements

There was a significant difference within (Wilcoxon, p<0.001) and between the groups (Mann–Whitney U test, p<0.001) in the flexion of right and left knee joints after the intervention with higher effect size in the yoga than in the control group.

Tenderness, swelling, and crepitus also showed a significant difference within (Wilcoxon, p<0.001) and between the groups (Mann–Whitney U test, p<0.001) after the intervention with higher effect size in the yoga than in the control group.

Walking time

There was a significant difference in walking time within (Wilcoxon, p<0.001) and between the groups (Mann–Whitney U test, p<0.001) after the intervention with higher effect size in the yoga than in the control group.

Discussion

This randomized two-armed parallel controlled trial on 250 participants included patients of both genders in the age group of 35–80 years with OA of the knee joints. Results showed significantly better improvement in the yoga than in the control group on all variables (p<0.001, Mann–Whitney) (i.e., walking pain, knee flexion, walking time, tenderness, swelling, crepitus, and knee disability.

Pain reduction

The reduction in walking pain observed in this study points to the beneficial effect of yoga as an add-on therapy to conventional physiotherapy practices.

In a pilot study on OA knees, Kolasinski et al.¹³ used a specific sequence of asanas based on the teachings of Iyengar for 8 weeks. They measured the pain by WOMAC with a significant reduction (p< 0.04) in pain by 46.7%. In another pilot study on yoga for OA knees, Ranjita and Nagarathna (unpublished observations) used a set of integrated yoga therapy program similar to the current study in a nonresidential camp set up for 1 week without any physiotherapy intervention. They showed a 40% reduction (from 6.59±2.24 to 3.97±2.44) in resting pain after yoga. In the current study, yoga was added after the standard physiotherapy, which showed a reduction in walking pain scores by 37.3% and 65% after 15 and 90 days, respectively.

The baseline pain scores were much higher in the current study (9.54±0.61) than in Ranjita's study (6.59±2.24). This difference is because Ranjita recorded the resting pain and the current study documented the pain while walking. However, the degree of changes appears to be similar in all the three yoga studies (37%–47%). This may point to the efficacy of yoga when used with or without a session of physiotherapy before the practice of yoga.

Similar effects of pain reduction have been observed by Garfinkel et al.²⁶ in an RCT on yoga for carpal tunnel syndrome, wherein the mean numerical rating scale (NRS) scores for pain decreased significantly (p=0.02) from 5.0 to 2.9 mm. Tekur et al.²⁷ studied the efficacy of an integrated approach of yoga therapy (IAYT) in patients with chronic low back pain which included several cases of spondylosis of the spine and documented 48.8 % reduction in NRS scores in the yoga group within 1 week of A residential program without offering any physiotherapy intervention. Garfinkel et al.¹² looked at the effect of Iyengar yoga in OA hands. Pre–post difference in mean scores of “pain during activity” in their study was similar (4.29) to the current study (3.56 at the second week and 6.19 at 3 months). However, they did not observe a significant difference between groups in tenderness, swelling, or hand functions, whereas these variables were significantly better in yoga than controls in the current study.

Knee disability score

In Kolasinski's study on OA knees¹³ there was a reduction in WOMAC knee disability score by 44% (p<0.04). In the present study, the disability reduced by 60% to 83% on the 15th and 90th day in the yoga group. In the Ranjita and Nagarathna (unpublished observations) study of 1 week of intensive yoga without physiotherapy, there was improvement in performance-oriented mobility (45%) and also in the “Timed up and Go” test (28% in “number of steps” and 30% in “time taken”). Haslock et al.,²⁸ in their controlled study on IAYT for patients who had a severe degree of rheumatoid arthritis and who had secondary OA, also showed a significant reduction in pain and functional disability, with 63% (left) and 66% (right) increase in hand grip strength in the yoga group as compared to an increase of 5% and 8% in their control group.

Walking time

The study by Kolasinski et al.¹³ on Iyengar yoga for OA knees did not show any improvement in the walking time, whereas the current study observed significant reduction in walking time by 27% after 15 days and 53% after 90 days of IAYT. Fisher et al.²⁹ measured the effects of a quantitative progressive exercise muscle rehabilitation program that was added to a physical therapy program and observed significant decreases in walking time and pain experienced during activities.

Mechanisms

Activation of pain fibers (unmyelinated and small myelinated) found in the joint capsules, ligaments, synovium, bone, and the outer edges of the menisci, increased intramedullary tension, subchondral microfractures, osteophyte formation, and flexion contractures due to OA changes are the major factors that cause pain.³⁰ Decreased muscular stamina and muscle spasm are additional factors that can aggravate pain and disability. The actual experience of pain is a psychologic phenomenon that has several additional central processes that include affective, behavioral, and cognitive factors.³¹ The multifactorial approach of yoga comprises practices that involve not only physical practices (asanas) that may provide benefits locally at the joint level but also includes breathing (pranayama), meditation (dharana and dhyana), introspective intellectual (jnana yoga) and emotion management (bhakti yoga) practices that promote healthy behavioral and lifestyle changes.

Muscle strengthening is the key component of exercises for OA since muscle weakness is one of the major causes of pain and disability. Studies have demonstrated the efficacy of exercise programs in improving muscle strength, flexibility, mobility, and coordination in patients with OA of knee and hip joints.^32
–34 There are several studies that have demonstrated better muscular stamina and strength³⁵ as well as steadiness and flexibility³⁶ after yoga in normal volunteers. This has been observed in patients with rheumatoid arthritis also.²⁸ The correct way of positioning the body in space at rest and during motion achieved through introspective body awareness differentiates yoga from physical exercises. The stress-reducing effect of yoga seems to be the other major mechanism of its efficacy in pain management in these patients.³⁷

Strengths of the study

Good sample size, randomized controlled design, active supervised intervention for the control group for the same duration as the experimental group, and follow-up for 3 months with good compliance (6% dropouts) are the strengths of this study. The results of this study have shown marked differences on all the variables between the groups and thus offer strong evidence for incorporating this yoga module for the management of OA knees by clinicians.

Limitations of the study

The study was on a select group who presented to a specialty orthopedic center and hence is not generalizable.

Suggestions for future work

A longer follow-up of ≥12 months is necessary to check for long-term efficacy and long-term acceptability. Studies using magnetic resonance imaging and biochemical variables may throw a better light on the mechanisms.

Conclusions

An adjunctive program with an integrated approach of hatha yoga therapy for OA knees reduces walking pain, tenderness, swelling, crepitus, disability, and walking time, and increases the range of flexion better than the therapeutic exercises. It thus offers a good value addition as a nonpharmacological intervention in the management of OA knees.

Footnotes

Acknowledgments

We are thankful to Dr. Ravi Kulkarni, statistician; Dr. Yogitha, Mrs. Pragati, and Mr. Rangaji, yoga therapists; and Mr. Zafar and Mr. Vishwanath, physiotherapists, who helped us in conducting this study. We gratefully acknowledge the help of all the staff members of SVYASA and Ebnezar orthopedic center for their cooperation in conducting and funding this study.

Disclosure Statement

No competing financial interests exist.

References

Felson

. An update on the pathogenesis and epidemiology of osteoarthritis. Radiol Clin North Am, 2004; 42:1–9.

Felson

, Lawrence

, Dieppe

. Osteoarthritis: New insights. Part 1: The disease and its risk factors. Ann Intern Med, 2000; 133:635–664.

Lawrence

, Bremmer

, Bier

. Osteoarthrosis: Prevalence in the population and relationship between symptoms and x-ray changes. Ann Rheum Dis, 1966; 25:1–24.

Chopra

, Patil

, Bilampelly

. Prevalence of rheumatic disease in rural population in Western India: A WHO-ILAR-COPCORD study. J Assoc Physicians India, 2001; 49:240–246.

Altman

, Hochberg

, Moskowitz

. Recommendations for the medical management of osteoarthritis of the hip and knee: New OA practice management guidelines from the ACR. Arthritis Rheum, 2000; 43:1905–1915.

Pendleton

, Arden

, Dougados

. EULAR recommendations for the management of osteoarthritis: Report of task force standing committee for International Clinical Studies including Therapeutic Trials (ESCISIT) Ann Rheum Dis, 2000; 59:936–944.

Singh

. Recent considerations in non-steroidal anti-inflammatory drug gastropathy. Am J Med, 1998; 105.

Griffin

. Epidemiology of non-steroidal anti-inflammatory drug associated gastrointestinal injury. Am J Med, 1998; 104:23S–29S.

Luskin

, Newell

, Griffith

. A review of mind/body therapies in the treatment of musculoskeletal disorders with implications for the elderly. Altern Ther Health Med, 2000; 6:46–56.

10.

Bjordal

, Johnson

, Rodrigo

. Short-term efficacy of physical interventions in osteoarthritic knee pain: A systematic review and meta-analysis of randomized placebo-controlled trials. BMC Musculoskelet Disord, 2007; 8:51.

11.

Garfinkel

. Yoga as a complementary therapy. Geriatrics Aging, 2006; 9:190–194.

12.

Garfinkel

, Schumacher

, Husain

. Evaluation of a yoga based regimen for treatment of osteoarthritis of the hands. J Rheumatol, 1994; 21:2341–2343.

13.

Kolasinski

, Garfinkel

, Tsai

. Iyengar yoga for treating symptoms of osteoarthritis of the knees: A pilot study. J Altern Complement Med, 2005; 11:689–693.

14.

Deyle

, Allison

, Matckel

et al. Physical therapy treatment effectiveness for osteoarthritis of the knee: A randomized comparison of supervised clinical exercise and manual therapy procedures versus a home exercise program. Phys Ther, 2005; 85:1301–1317.

15.

Berman

, Lao

, Langenberg

et al. Effectiveness of acupuncture as adjunctive therapy in osteoarthritis of the knee: A randomized, controlled trial. Ann Intern Med, 2004; 141:901–910.

16.

Bookman

, Williams

, Shainhouse

. Effect of topical diclofenac solution for relieving symptoms of primary osteoarthritis of the knee: A randomized controlled trial. CMAJ, 2004; 171:333–338.

17.

Altman

, Asch

, Bloch

. Development of criteria for the classification and reporting of osteoarthritis: Classification of the osteoarthritis of the knee. Arthritis Rheum, 1986; 29:1039–1049.

18.

Kellgren

, Lawrence

. Radiological assessment of osteo-arthrosis. Ann Rheum Dis, 1957; 16:494–502.

19.

Nagarathna

, Nagendra

. Yoga for Promotion of Positive Health. Bangalore: Swami Vivekananda Yoga Prakashana, 2000.

20.

Nagarathna

, Nagendra

. Yoga for Arthritis. Bangalore: Swami Vivekananda Yoga Prakashana, 2001.

21.

Telles

, Nagarathna

, Nagendra

. Breathing through a particular nostril can alter metabolism and autonomic activities. Indian J Physiol Pharmacol, 1994; 38:133–137.

22.

Telles

, Nagarathna

, Nagendra

. Autonomic changes during Om meditation. Indian J Physiol Pharmacol, 1995; 39:418–420.

23.

Pollard

. Preliminary validity study of the pain disability index. Percept or Index, 1984; 59:974.

24.

Bellamy

, Buchanan

, Goldsmith

. Validation study of WOMAC: A health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. J Rheumatol, 1988; 15:1833–1840.

25.

Swash

, Glynn

. Hutchinson Clinical Manual, 22nd. London: Elsevier Publications, 2005.

26.

Garfinkel

, Singhal

, Katz

. Yoga-based intervention for carpal tunnel syndrome: A randomized trial. JAMA, 1998; 280:1601–1603.

27.

Tekur

, Singhpow

, Nagarathna

. Effect of short term intensive yoga program on pain, functional disability, and spinal flexibility in chronic low back pain: A randomized control study. J Altern Complement Med, 2008; 14:637–644.

28.

Haslock

, Monro

, Nagarathna

. Measuring the effect of yoga in rheumatoid arthritis. B J Rheumatol, 1994; 33:788.

29.

Fisher

, Gresham

, Pendergast

. Effects of a quantitative progressive rehabilitation program applied unilaterally to the osteoarthritic knee. Arch Phys Med Rehabil, 1993; 74:1319–1326.

30.

Felson

. The sources of pain in knee osteoarthritis. Curr Opin Rheumatol, 2005; 17:624–628.

31.

Burton

, Allen

, Bird

, Faragher

. Bridging the gap: Ageing, pharmacokinetics and pharmacodynamics. J Pharm Pharmacol, 2005; 57:671–679.

32.

Ettinger

, Bums

, Messier

. A randomized trial comparing aerobic exercise and resistance exercise with a health education program in older adults with knee osteoarthritis: The Fitness Arthritis and Seniors Trial (FAST) JAMA, 1997; 277:25–31.

33.

Pies

, Philbin

, Groff

. Relationship between gonarthrosis and cardiovascular fitness. Clin Orthop, 1995; 313:169–176.

34.

Bashaw

, Tingstad

. Rehabilitation of the osteoarthritic patient: Focus on the knee. Clin Sports Med, 2005; 24:101–131.

35.

Dash

, Telles

. Improvement in hand grip strength in normal volunteers and rheumatoid patients following yoga training. Indian J Physiol Pharmacol, 2001; 45:355–360.

36.

Raghuraj

, Telles

. Muscle power, dexterity skills and visual perception in community home girls trained in yoga or sports and in regular school girls. Indian J Physiol Pharmacol, 1997; 31:409–415.

37.

Perlman

, Sabina

, Williams

. Massage therapy for osteoarthritis of the knee: A randomized controlled trial. Arch Intern Med, 2006; 166:2533–2538.