Comparison of the Efficacy of Stretching and Isometric Exercises Versus Manual Traction and Isometric Exercises on Knee Pain and Functional Activities in Tibiofemoral Osteoarthritis

Introduction

Osteoarthritis (OA) is one of the most prevalent articular disorders affecting humankind and a major cause of disability and socioeconomic burden. It mainly affects the elderly population, resulting in pain, loss of function and changes related to quality of life.¹ Clinically, the disorder is characterised by joint pain, tenderness, difficulty in motion, crepitus, occasional effusion and variable stages of local inflammation; however, it does not cause any systemic effects.

Degenerative osteoarthritis is more common in women than in men and tends to worsen with age. If left untreated, the disease may increase the tendency of falls and decrease longevity.² Based on X-ray data, it is believed that tibiofemoral osteoarthritis is more common than patellofemoral osteoarthritis. Within the Framingham cohort, patellofemoral osteoarthritis was observed in 5%, tibiofemoral osteoarthritis in 23% and combined tibiofemoral and patellofemoral in 20%.³ The ratios of prevalence and incidence in females and males were 1.69 and 1.39, respectively. The various signs of osteoarthritis include bony swelling, synovial effusion, crepitus (sensation of bone rubbing against bone on movement), restricted movement, deformity of joints, muscle weakness, muscle wasting and joint instability, while the symptoms include pain, stiffness, functional impairment.^4,5 X-rays are the primary diagnostic tool; however, arthroscopy, ultrasound, MRI, CT scan etc., are also utilized.⁶ Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), used as an outcome measure in Asian patients with knee or hip osteoarthritis has been found to be a valid and reliable tool for assessing outcomes in this population. The WOMAC index requires the patients to report information in three dimensions - pain, stiffness and physical function. It is a useful measurement tool for assessing the perception of the patients regarding their treatment, both before and after the intervention.⁷ Visual Analogue Scale (VAS) is used as an outcome measure for measuring the pain intensity, consisting of a 10 cm line marked with numbers 0 to 10, with 0 representing no pain and 10 representing maximum pain. The subject is asked to mark his/her pain on this line as per the severity.⁸ The medical management includes prescription of soluble aspirin for pain relief and reduction of synovitis. An analgesic, particularly paracetamol is quite useful and in combination with dextropropoxyphene provides symptomatic relief. Salicylates are widely and effectively used in osteoarthritis.⁹ Physiotherapy management includes paraffin wax bath, continuous or pulsed shortwave diathermy, cryotherapy, transcutaneous electrical nerve stimulation (TENS), manual traction, strengthening exercises, stretching exercises.

Materials and Methods

The data for the study were collected from a hospital in Bangalore. A comparative study using simple random sampling method was conducted for three months. A sample size of 30 subjects was included in the study. The subjects were divided into two equal groups, with 15 subjects in each group. Group A with 15 subjects received stretching treatment along with isometric exercises, while Group B with 15 subjects received manual traction treatment along with isometric exercises. The subjects with unilateral knee pain, aged above 45 years, with radiographs showing possible or definite osteophytes and Grade 1 & 2 osteoarthritis according to Kellgren & Lawrence scale, were included in the study. The subjects with knee deformities, previous history of knee surgery, joint infections in lower extremities, ligament injury in lower extremities, malignancy, open wounds in lower extremities & unhealed fractures in lower extremities were excluded from the study.

Evaluation

Outcome measures were obtained on the first day before the treatment and on the 7th day post treatment and were compared for analysis. The baseline measurements were recorded using VAS, WOMAC scales after providing appropriate instructions to the subjects.

Intervention

Both the treatment programs were scheduled thrice a week over a period of 15 days (total seven sessions).

Group A treatment (Stretching) - This treatment included hamstrings stretch, quadriceps stretch and calf stretch.

Group B treatment (Manual traction) - This treatment included manual traction to knee.

Both Group A & Group B treatment (Isometric exercises) - This treatment included isometric exercises for hamstrings, quadriceps, vastus medialis oblique, gluteals, abductors of hip and adductors of hip.

Results

Statistical method

• Descriptive and interferential statistical analysis were conducted.

• Results on continuous measurements were represented as mean, standard deviation and the results on categorical measurements were represented in number (%).

• Level of significance was set at P <0.05.

Assumptions

1. Dependent variables were normally distributed.

2. Samples drawn from the population were random.

3. Cases of the samples were independent.

• Student’s’ test (two tailed, independent) was used to determine the significance of study parameters on a continuous scale between the groups (Intergroup analysis), in metric parameters.

• Paired ‘t’ test was used to determine the significance of study parameters on a continuous scale within each group.

Comparison of VAS scores

The mean and SD at baseline did not show significant difference in both the groups (Group A=4.07±0.88, Group B=3.73 ± 0.80 ). Significant changes were observed post intervention in both the groups (Group A=2.80±0.94, Group B=1.27±0.46) with P=0.00. Group A showed a difference of 1.27±0.06 and Group B showed 2.47±0.34 within the group. Between the group analysis showed a significant difference of 1.2 in Group B compared to Group A with P=0.00 (Table 1).

Comparison of pain scores

The mean and standard deviation of pain scores (Group A= 16.40±1.76, Group B=15.53±1.68) at baseline showed no significant difference between the groups. Both Group A and Group B showed improvement in pain post intervention (Group A= 11.60±1.35, Group B=6.47±1.73) with P=0.00. In Group A, pain reduced by 4.80±0.41 and in Group B by 9.07±0.04. Intergroup analysis showed a significant difference of 4.27 in Group B compared to Group A with P=0.00 (Table 2).

Comparison of stiffness scores

The mean and standard deviation at baseline did not show significant changes in both the groups (Group A=6.33±0.72, Group B=5.87±0.83). Considerable changes have been found post intervention in both the groups (Group A=4.73±0.80, Group B =2.73±0.80) with P=0.00. In Group A, stiffness reduced by 1.60±0.08 and in Group B by 3.13±0.04 within the group. Between the group analysis showed a difference of 1.53 points in Group B compared to Group A, which was clinically significant with P=0.00 (Table 3).

Comparison of function scores

The mean and standard deviation at baseline did not show significant changes in both the groups (Group A=52.33±7.32, Group B=52.47±5.91). Considerable changes were noticed post intervention in both the groups (Group A=36.60±6.54, Group B=25.53±5.21) with P=0.00. In Group A, function reduced by 15.73±0.77 and in Group B by 26.93±0.71. Between the group analysis showed a difference of 11.2 points in Group B compared to Group A, which was clinically significant with P=0.00 (Table 4).

Comparison of WOMAC scores

The mean and standard deviation at baseline showed significant differences between the groups (Group A=75.07±8.14, Group B=73.87±5.99). Considerable changes were noted post intervention in both the groups (Group A=52.93±6.68, Group B=34.73±5.19) with P=0.00. In Group A, WOMAC scores reduced by 22.13±1.46 and in Group B by 39.13±0.80. Intergroup analysis showed a difference of 17 points in Group B compared to Group A and this was clinically significant with P=0.00 (Table 5) (Figure 1).

Discussion

The aim of the present study was to compare the effectiveness of stretching with isometric exercises versus manual traction with isometric exercises on pain and functional activities of knee in subjects with tibiofemoral osteoarthritis.

A total of 30 subjects satisfying the inclusion and exclusion criteria were randomly divided into two groups (Group A and Group B) with 15 subjects assigned to each group. Informed consent was obtained from the patients. Pre-test scores using VAS (for pain) and WOMAC (for functional activities) were recorded. A brief introduction of stretching, manual traction and isometric exercises was given to the subjects.

Group A: After a brief demonstration, subjects performed stretching with isometric exercises thrice a week for a period of 15 days (seven treatment sessions).

Group B: After a brief demonstration, subjects performed manual traction with isometric exercises thrice a week for a period of 15 days (seven treatment sessions).

The previously conducted research has demonstrated significant improvements with manual traction, stretching and isometric exercises. The present study investigated the combined beneficial effects of stretching with isometric exercises (Group A) versus manual traction with isometric exercises (Group B), which showed significant improvements in both the groups. However, Group B i.e., manual traction with isometric exercises showed highly significant results compared to Group A i.e., stretching with isometric exercises.

The pre-treatment values of VAS (for pain) and WOMAC (for functional activity) from baseline to seventh day were assessed. These values were statistically analyzed using repeated measures of paired ‘t’ test and unpaired ‘t’ test. The statistical analysis done for both the groups showed reduction in pain intensity and improvement in functional activity. The subjects in Group B showed significant improvements in pain and functional activity from baseline to 7th day of treatment. While the subjects in Group A also showed improvements from baseline to 7th day, the amount of reduction in pain intensity and improvement in functional activity was greater in Group B compared to Group A. Thus, Group B treated with manual traction combined with isometric exercises showed greater improvements when compared with Group A treated with stretching combined with isometric exercises.

The strength of the quadriceps musculature is one of the intrinsic elements that has been proven to have an effect on the knee joint function. It is evident that lower extremity strength has a primary function in knee joint shock attenuation at some point of weight bearing activities. However, the research concerning investigation of the role of strengthening in the treatment of OA of the knee continues to be ongoing. There may be an increased risk of development or progression of disease due to excessive or uncontrolled loading on the joint. Consequently, quadriceps strength needs to be taken into consideration in the studies of knee OA. Reduction in quadriceps strength has been proven to be associated with OA of knee. The primary purpose of any treatment approach in the management of knee OA is to alleviate pain and disability. Combination of both pharmacological and non-pharmacological treatment methods is frequently preferred. The Osteoarthritis Research Society International (OARSI) endorsed non-pharmacological techniques including patient education programs, weight reduction, coping techniques and workout programs for the treatment of knee OA. Norden, Leventhal and Schumacher observed that ‘isometric exercises’ are easy, and inexpensive to perform and they swiftly improve strength. The outcomes of this study were strongly supported by evidence from a study conducted by Antony Leo (1990). The purpose of his experimental study was to investigate the effectiveness of manual traction on the pain, range of movement and the functional outcome in knee joint osteoarthritis.

Limitations

• Relatively small sample size.

• No follow-up examinations were conducted. Results were assessed only after the 7th day of intervention.

• Outcomes of this study may not be generalizable to individuals with higher levels of pain or lower levels of functional activity.

• Medication usage was not assessed which could influence the treatment.

• This study did not include an assessment of the range of motion. Incorporating range of motion could have provided additional insights into participant’s movement.

• Data outcome cannot be justified for both the genders, as the subjects included were predominantly females.

• No objective outcome measures were considered in the study.

Further recommendations

• Further studies with a larger sample population need to be undertaken.

• The study can be extended to draw comparisons with other treatments.

• The same study could be conducted using an objective outcome measure to assess the range of motion.

Conclusion

This study demonstrated that both manual traction with isometric exercises and stretching with isometric exercises showed significant reduction in pain and improvement in functional activities of knee in subjects with tibiofemoral osteoarthritis. However, the subjects receiving manual traction with isometric exercises showed better improvement in pain and functional activities of knee based on mean values and reduction in VAS and WOMAC scores when compared to stretching with isometric exercises in subjects with tibiofemoral osteoarthritis. Hence, this study rejects the null hypothesis and accepts the alternate hypothesis that the manual traction with isometric exercises is more effective than stretching with isometric exercises on pain and functional activities of knee in subjects with tibiofemoral osteoarthritis. Thus, we conclude that manual traction with isometric exercises is effective than stretching with isometric exercises in reducing pain and improving functional activity of knee in subjects with tibiofemoral osteoarthritis.

Conflict of Interest

None