Various rehabilitation methods are used to manage chronic lower back pain (LBP), and the methods can be mainly divided into non-exercise methods (e.g., diathermy, transcutaneous electrical nerve stimulation (TENS), therapeutic ultrasound, traction) and exercise training based treatment (e.g., manual therapy involving stretching/strengthening/stabilization, yoga, and cognitive-behavioral therapy) [1-4]. Unlike in the past, in today’s digital society, digital intervention based on websites or applications (“apps”) is expected to have the benefits of both easier accessibility and cost-effectiveness. As chronic LBP is characterized a recurrent course, it requires steady rehabilitation for successful management, and utilizing these updated technologies would be beneficial.

Most people experience LBP more than once in their lifetimes, and in about 23% of cases, symptoms are chronic, lasting for more than 12 weeks [1], and persist for up to a year in 65% of these cases [5,6]. About 11∼12% of patients with chronic LBP suffer from daily activity impairments, which adversely affect social life, mental health, and eventually degrade quality of life [1]. The experience of pain instills fear, inducing LBP sufferers to avoid movement or activities resulting in worsening pain and a vicious cycle [7]. Present clinical guidelines for chronic LBP management recommend exercise as a first-line treatment [8,9]. Many studies have reported improvement in pain and disability in the group that performed physical therapy relative to the group that did not [10,11].

Since chronic LBP, a chronic disease, eventually needs to be managed through steady physical therapy, various attempts are being made to find a more cost-effective and accessible rehabilitation treatment method. As an example various apps such as Fitbit, Kaya, Snapcare, and Fitback have been developed for patients with low back pain, and there are reports that the degree of pain or disability is reduced when these digital tools are used [12-15]. However, most of these are provided for a cost, and there may be limitations for middle-aged and elderly people with poor smartphone usage ability to actively use the app. In fact, in related studies, the average age of the participants was 30’s∼50’s. We configured a rehabilitation program so that the doctor in charge issues an exercise prescription tailored to the individual condition of the chronic low back pain patient, and the patient is provided with a QR code for the prescribed exercise so that he or she can easily watch the exercise video on YouTube for free. And in a nationwide lock-down period due to COVID-19 pandemic since in March 2020, telecommuting increases and social isolation is prevalent, and the prevalence and intensity of LBP were reported to have increased [16-18]. In this special situation, digital rehabilitation has distinct advantages. This study was conducted at home during the COVID-19 lock-down period for 30-week follow-up.

The aim of this study was to confirm that online-based digital intervention is effective in treating chronic LBP without having to go to a hospital to receive exercise therapy. The primary outcome was a change in the intensity of pain and the secondary outcome was a change in the degree of disability. We analyzed the short-term and long-term effects of this intervention by assessing changes in the degree of pain and disability over a 30-week follow-up.

1. Design

The study was a prospective clinical trial. The trial was conducted at a single tertiary medical spine center. Subjects comprised patients who visited the spine center for chronic LBP from February 2020 to January 2021. This study was conducted in compliance with the relevant laws and a clinical trial protocol approved by the Institutional Review Board of tertiary hospital.

2. Participants

Criteria for selecting subjects were as follows: (1) men or women over the age of 18, who (2) had suffered from LBP for more than 12 weeks, (3) had sufficient cognitive and manipulation skills to watch videos and exercise, (5) had adequate equipment and space to exercise while watching videos at home, and (6) provided voluntary informed consent to participate in this study after the objectives and methods of the clinical study were explained. Exclusion criteria are as follows: (1) red flag signs of severe pathologic status (i.e. fracture, tumor, infection, or cauda equine syndrome), (2) in an acute flare-up stage, (3) unable to perform rehabilitation treatment due to severe LBP or decreased cognitive function or physical function, (4) history of spinal surgery, (5) presence of disc herniation or spinal stenosis that required surgery, and (6) presence of underlying rheumatic diseases.

3. Interventions

A total of 26 videos were produced by two board-certified rehabilitation medicine specialists with more than 20 years of clinical expertise in the musculoskeletal field (Table 1). Each video was 4∼6 minutes long and a QR code (Fig. 1) was provided to participants to watch the online video prescribed to them. A personalized exercise prescription was provided by physicians based on the participants individual conditions, and they received detailed exercise instructions. Participants were instructed to exercise while watching the prescribed video. The exercise prescription was renewed based on assessment of the partic ipants condition including self-report questionnaires and physical examination. This process was repeated every 4 weeks and exercises were performed for more than 30 weeks. Aerobic exercise, stretching, and lumbar strengthening exercises were prescribed separately. Although the effect of aerobic exercise on back pain is still unclear, aerobic exercise was recommended to improve overall health condition through regular physical activity. For example of exercise prescription, in the case of aerobic exercise, a fast walk of at least 30 minutes per session for at least 150 minutes per week was prescribed. For stretching, knee to chest stretching and McKenzie extension exercises were prescribed as follows: six repetitions a set, three sets a day, to be performed three times a week. Lumbar strengthening exercises involved eight curl-up exercises per set for three sets per day to be performed three times a week.

Table 1 . List of YouTube Exercise Videos Provided to Patients.

Contents
Education
How to exercise using on-line video
Explanation and importance of good posture
Understanding the natural course of back pain
Aerobic exercise
Method and intensity of aerobic exercise
Stretching exercise
Hamstring stretch
Iliopsoas stretch I, II
Knee to chest stretch
McKenzie extension
Pelvic tilt stretch
Iliotibial band stretch
Piriformis stretch
Strengthening exercise for lumbar stabilization
Core strengthening exercise
Curl up exercise
Squat exercise
Flank exercise
Bird dog exercise
Bridge exercise

Figure 1. QR code list for YouTube videos.

Videos consisted of instructions to help the participants understand their pain and demonstrations of aerobic exercises, stretching for relaxation, and exercises for lumbar and pelvis stabilization. First, all participants watched an introduction video to help them understanding the pathophysiology of LBP and its natural course before starting their prescribed exercises. The importance of maintaining correct posture and maintaining their exercise regime was emphasized. For aerobic exercise, degree of intensity was explained in an easy-to-understand manner, and generally moderate-intensity was recommended in addition to personalized target heart rates as well as frequencies and durations of the prescribed exercises. Seven stretching methods for lumbar spine stabilization and six muscle strengthening exercises for lumbar spine stabilization were employed. Proper posture, execution time, rest time between sessions, and number of repetitions were explained for each motion, and motions were repeatedly demonstrated and precautions for each motion were provided. Some exercise motions in the video are listed in Fig. 2.

Figure 2. Examples of exercise demonstration. (A, B) Explanation and importance of good posture. (C) Hamstring stretch. (D, E) Iliopsoas stretch I, II. (F) Iliotibial band stretch. (G) Piriformis stretch. (H) Squat exercise. (I) Side flank exercise. (J) Bird dog exercise.

During the intervention period, no evaluation was conducted on how regularly exercise was performed, but those who regularly visited outpatient clinic were judged to have a good compliance.

4. Outcomes

After providing informed consent, a baseline evaluation was carried out. Re-evaluation was performed through self-report questionnaires when visiting the outpatient clinic at 8∼20 weeks (short term follow-up) and after 30 weeks (long term follow-up). Pain intensity was evaluated using a numeric rating scale (NRS) (0 to 10, 0 representing no pain and 10 indicating the worst pain possible). To measure changes in pain intensity, participants were asked to rate their LBP intensity. Level of disability was evaluated using the Roland-Morris Disability Questionnaire (RMDQ), which consists of 24 items (0 to 24 with 0 indicating no disability and 24 indicating the most disability). RMDQ is one of the most widely used tools to evaluate the functional status of patients with LBP [19,20]. The RMDQ is a 24-item questionnaire covering disease-specific daily living impairments such as personal care, work, outdoor activity, mood, and sleep.

5. Statistic analyses

Data were analyzed statistically using SPSS ver. 28.0 software (IBM Corp., Armonk, NY, USA). One-way repeated measures analysis of variance (ANOVA) followed by post hoc analyses with Bonferroni correction for all pairwise comparisons was performed to investigate if there were significant changes in NRS and RMDQ compared to baselines. The significance level was set at 0.05.

A total of 36 patients who fulfilled the inclusion criteria provided informed consent to participate in this study (Fig. 3). Eleven participants did not complete the study until 30 weeks. Among them, eight were lost to follow-up, two had co-morbidity-related problems. And one participant back pain deteriorated during daily life without trauma, and aggravation of herniated nucleus pulposus (HNP) at L4-5 was observed on lumbar spine magnetic resonance imaging (MRI) and surgically treated. Ultimately, 25 participants (69.4%) completed the full-term evaluation. There were no participant-reported adverse effects.

Figure 3. Study inclusion and exclusion flowchart. Patients with low back pain for more than 12 weeks without acute flare-up were included to this study. A total of 25 patients completed the study.

Mean participants age was 51.48 years (range, 23 to 77 years), 60% were over 50s, and 72% were female (Table 2). The treatments related information that participants were receiving right before or at the time of participation in the study such as oral medication/manual therapy/physical modality, and the epidemiology of LBP determined based on spine X-ray and MRI are listed in Table 2. Initial mean NRS was 3.96 ± 2.47. NRS was better in 14 of 25 participants at the short term follow-up and in 21 of 25 participants at the long term follow-up. There was a statistically significant three-way interaction between time and NRS, short term intervention, and long term intervention (F = [1.3, 32.26] = 20.234, p<.001) (Fig. 4). Initial mean RMDQ score was 4.2 (SD ± 3.63). RMDQ score had improved in 10 of 25 participants at both the short- and long-term follow-ups. However, there were no significant differences in RMDQ scores between baseline, short-term follow-up, and long-term follow-up (F = [1.34, 25.63] = 19.197, p=0.132) (Fig. 4).

Table 2 . Participants General Characteristics and Epidemiology of Low Back Pain.

N	25
Age (years), median	51.48
Range	23∼77
≥50	15 (60%)
<50	10 (40%)
Gender (% female)	72
Epidemiology of LBP
Intervertebral disc degeneration	15
Spondylosis	11
Spinal stenosis	8
Spondylolisthesis	6
Facet joint dysfunction	3
Sacroiliac joint dysfunction	1
Preceding and concomitant treatments
Medication	17
Manual therapy	4
Physical modality	2
None	6

Figure 4. Effect of online-based self-exercise as assessed by PRS and RMDQ scores. One-way repeated measures analysis of variance (ANOVA) found significant effects on PRS (F = [1.3, 32.26] = 20.234, p<.001) and post hoc analyses showed significant differences between baseline, short term follow-up, and long term follow-up. However there was no significant differences in RMDQ scores between the three groups (F = [1.34, 25.63] = 19.197, p=0.132). All data are shown as mean values with standard deviations. NRS: numeric rating score, RMDQ: roland-morris disability questionnaire.

In this study, online-based digital intervention including education and exercise training were prescribed for chronic LBP patients via YouTube videos produced by experienced rehabilitation medicine physicians; pain intensity improved significantly over both the short term and long term in these participants, but there were no significant changes in disability after this intervention.

Continuity is required for the management of chronic diseases, which account for the majority of diseases in patients middle age and older, and online-based rehabilitation treatments have attracted interest because of their accessibility and cost-effectiveness. Various online-based rehabilitation programs have been devised for management of a variety of chronic diseases [21]. For example, heart failure patients that watched disease-specific educational videos after hospital discharge showed improved self-care maintenance compared to those patients who did not watch these videos [22]. In stroke patients, stroke literacy was improved by video-based educational intervention [23]. In Parkinson’s disease patients, mobile application-based E-virtual rehabilitation had a positive effect on the overall motor symptoms of Parkinson’s disease [24].

For patients with chronic LBP, exercise therapy has been identified as an effective intervention. As continuous exercise therapy is required, studies on intervention methods have been conducted. Bronfort et al. [25] studied the effects of directly supervised physical therapy versus self-home exercise, and pain intensity as assessed by NRS and disability as assessed by RMDQ were reduced to a greater extent in the supervised group than the control group but with but no statistically significant difference over the short term (12 weeks) or long term (52 weeks). Guillermo et al. [26] studied efficacy of a supervised versus non-supervised physical therapy for 24-week follow-up, and similar results were obtained. This suggest that supervised physical training by a therapist in not necessarily essential for patients with LBP.

In recent years, several mobile applications targeting low back pain patients have been developed [13]. Toelle et al. [27] showed NRS improved significantly in the intervention group that used the app compared to the group that received independent physical therapy for 12 weeks. Hörder et al. [28] showed a mobile app-based video exercise program was associated with a median pain reduction of 2 points using the NRS scale and a 4.1 point improvement in disability as assessed by ODI; these reductions were significant at three months follow-up. Biofeedback has also been reported to be effective at improving pain and disability in patients with low back pain provided with wearable motion-sensors [29].

In this study, we produced exercise training videos 4∼6 minutes in length for patients using the YouTube platform, and provided patients with a QR code that linked to their individualized exercise video. The QR code allowed elderly participants or participants unfamiliar with mobile devices to watch their video without difficulty. We produced an educational video regarding the pathophysiology of back pain and all participants first watched the video before they engaged in their prescribed exercises. Since a number of studies have reported that pain pathophysiology education can improve pain and exercise adherence [30,31].

We expected pain and physical disability to improve upon performance of our online-based home exercise routine, but RMDQ did not improve significantly from baseline. One reason for this may be that the mean RMDQ score at baseline was low at 4.2 points (SD ± 3.63), as our study was conducted on patients judged to be able to perform exercise therapy after pain was controlled to some extent through drug treatment. A total of 68% of participants were receiving other treatment such as oral medication, manual therapy, and physical therapy at or immediately before study participation (Table 2).

Another tool similar to the RMDQ used to assess the degree of disability in LBP patients is the Oswestry Disability Index (ODI). Fritz et al. [32] reported that a 50% reduction in ODI could be considered a successful outcome of an intervention. A meta-analysis reported no difference in the measurement properties of RMDQ and ODI in relation to the physical function of LBP patients [33]. We used the RMDQ because we think this tool will make a more intuitive assessment of the current situation since it checks each item as yes or no. When we substituted our findings and computed (RMDQinitial−RMDQpost)/RMDQinitial ×100, 8 of 25 participants (32%) showed a 50% improvement in disability score.

The baseline mean NRS in our study was 3.96 while the short and long term mean scores decreased to 2.92 and 1.56, respectively. The total reduction score was 2.4, which was statistically significant. Salaffi et al. [34] studied the clinically improved threshold level of mean NRS in chronic pain patients, it was 0.7 points with an initial NRS of 4 or less, 2.1 points with an initial NRS of more than 4 to 7, and 2.8 points with an initial NRS of more than 7 to 10. In addition, an improvement of 1.03 points changes after treatment in individuals in group with an NRS score of 4 to 10 were considered a clinical improvement in the other study [35]. In our study, patients with an NRS score of 4 or less showed an average improvement of 1.5 points, and patients with an NRS score of more than 4 showed an average improvement of 4.3 points, and the average of individual change values was 2 points in patients with an initial NRS score of 4 or more. Therefore, the improvement in pain intensity observed in this study can be considered significant. And as this study was conducted during COVID-19 lockdown periods, this results highlights how chronic LBP can be effectively managed with digital-based self-exercise therapy.

A major limitation of this study is that no evaluation was conducted on how regularly exercise was performed. We cannot ascertain that all the participants were carry out all exercises regularly at home, but we presumed those who regularly visited outpatient clinics and taking updated exercise prescriptions have good adhesion. The 69.5% adherence rate of our study is comparable to those of present studies, reported rates of self-exercise adherence range in recent studies from 50∼96% [25,26,36,37]. Known obstacles to performing home-based exercise or self-exercise include the lack of diversity in the exercise program and lack of feedback regarding whether the exercise is being performed correctly or not. If the patient feels that the effect of the exercise is insufficient, there is early cessation of exercise, lack of will, lack of regular performance of the exercise, pain, and depression among others [38]. Our participants were constantly encouraged on an outpatient basis, but did not receive reminders for regular exercise and were not provided with immediate feedback regarding if they were performing the exercises correctly. The cases of early discontinuation in our study are likely due to a combination of the factors listed above, and better results may be obtained if feedback is strengthened and reminders are used. And there was no control group to which compare the intervention group. As it is a study that has confirmed the long-term effect of more than 30 weeks, it is difficult to exclude the effect of improvement over the natural course of back pain. But according to systemic review about the natural course of low back pain, improvement in back pain has not been reported as a common outcome [39]. Specifically, in a longitudinal study followed for 8 years to determine the course of low back pain, 38% maintained similar intensity, decreased in 19%, increased in 17%, and 27% showed fluctuations [40]. Considering that chronic LBP tends to be maintained at a similar level rather than naturally improved, the effect of this exercise could be considered meaningful. And because of the low number of participants, further investigation with a larger sample size is needed to account for individual differences. Also, during the follow-up period, participants were not restricted or recommended to receive appropriate medication or physical therapy.

Online-based self-exercise had a significant effect on pain relief in chronic LBP patients. Additional studies are needed to determine what additional strategies can most effectively and cost-effectively manage chronic LBP.

We wish to acknowledge the financial support of the Catholic Medical Center Research Foundation in 2019. We would also like to express our thanks to Beom Jun Cho, Jaesoon Jeon, and Yeonjoo Park for helping with the video clips.

The authors have no potential conflicts of interest related to this research.

Jae Min Kim contributed to conception and design of this project. All authors contributed to data analysis, interpretation, drafting of the article, critical revision, and all authors approved the final version of the manuscript.