Study design

This study is experimental research using randomized controlled trial to identify the effects of hand pressed-pellet therapy on pain intensity, pain pressure threshold, and daily activities of elderly people complaining of chronic lower back pain.

Participants and randomization

This study was conducted from November 1, 2021, to January 30, 2022. Subjects using four elderly welfare facilities in A City, B City, S City, and I City were selected. The selection criteria were elderly people who were 65 years of age or older, those who complained of lower back pain for more than three months, those who could communicate and respond to questionnaires, and those who had no experience in hand pressed-pellet therapy. Exclusion criteria included those who were using other complementary and alternative therapies to relieve lower back pain, whose lower back pain was caused by cancer or a fracture, who had trauma or lesions on the hands, who had allergies, and who were currently receiving treatment for back pain.

The sample size for this study was calculated using the G*power 3.1 program. To calculate the sample size, we conservatively set the effect size to 0.7 based on the effect size reported in a previous study [13], which corresponds to a medium to large effect size according to the criteria presented by Cohen [22]. Additionally, the Type I error (α) was set at 0.05, and the power (1-β) was set at 0.8, which are commonly used standards in research [23], taking into consideration a balanced approach to the possibility of false positives and false negatives. A one-tailed t-test was used to calculate the necessary number of samples for an independent samples t-test. As a result, it was found that a total of 52 participants, with 26 participants in each of the experimental and placebo control groups, were needed. With an expected dropout rate of 20%, considering the coronavirus situation and the study period of six weeks, thirty-three participants were placed in the intervention group and thirty-three were placed in the placebo control group, for a total of sixty-six patients. Each facility randomly assigned participants to two groups using an Excel program. Each with thirty-three participants in the intervention group and thirty-three in the placebo control group. During the study, six patients in the intervention group and nine patients in the placebo control group dropped out due to coronavirus-related or personal circumstances. A total of fifty-one participants, twenty-seven in the intervention group and twenty-four in the placebo control group, were used to analyze the study results [Fig. 1].

Fig. 1Intervention

For the intervention of the pressed pellet, a silver-colored Seoambong (aluminum patch) product made of aluminum with small bumps the size of grains was used. Based on previous research [11,12,13, 24], the mediation was conducted once a week for a total of six times.

The researcher directly applied the pressed-pellet therapy to both hands based on the evidence that it is effective to do so. For the intervention group, the pressed-pellet therapy was applied at a total of eleven sites: D3, regulating blood for colon function; N5, for regulating liver function; J3, for regulating kidney function; I19/I20/I21 and N18, for muscle strengthening; A8, umbilical/abdominal muscle maintenance acupuncture points; H2, chiropractic acupuncture points directly related to lower back pain; I38, chiropractic points directly related to back pain and B7, lumbar vertebrae [Fig. 2]. In addition, the control group was also mediated with placebo hand pressed-pellet therapy. For the control group, the mediation was applied to a total of eleven sites that are unrelated to lower back pain: A28, nose tip; A24, under the chin; A20, Clavicle; A18, center of chest; A16, under the genitalia; A1, genitalia; B24/B2/B19, back of neck; and M11-2, shoulder blood duct [Fig. 2]. It was possible to maintain four hours of pressure or more [10, 25] when attaching the Seoambong, and the blood flow stimulated by the hand pressed pellet is shown in Fig. 2.

Fig. 2

Hand- press points used in intervention group and control group

For the preliminary investigation, the intervention group and the placebo control group were asked about general and health- and disease-related issues, pain intensity (using the visual analog scale, or VAS), pain level, personal care, transfer, walking, sitting, sleeping, standing, social activities, going out, and so on. The investigator used a questionnaire tool (K-ODI) related to activities of daily living. After participants had completed the questionnaire in the welfare facilities, the investigator measured the pain pressure threshold of the participants in the corresponding facilities. Every week, before the hand pressed-pellet intervention was performed, the research assistant checked the pain intensity, and then the investigator reviewed the discomfort and side effects at the intervention site, measured the pain pressure threshold, and performed the hand pressed-pellet intervention. One week after the end of the six hand pressed-pellet interventions, the research assistant surveyed the pain intensity (VAS) and daily living activity measurement tool (K-ODI) in the same way as the pre-examination method, and the investigator measured the pain pressure threshold and conducted a post-mortem survey.

InstrumentsVAS

In this study, pain intensity refers to the degree of pain the subject feels using the visual analog scale (VAS). A score of 0 indicates no pain, and a score of 10 indicates severe pain; overall, a lower score indicates less pain.

PPTs

In this study, pain pressure threshold was measured using a pressure painometer, specifically, the Compact Digital Algometer (pain test EPX25 Algometer, Wagner Instrument, USA). PPT is defined as the minimum amount of pressure necessary to elicit pain or discomfort. The pressure is applied perpendicularly to the skin at a constant rate of increase until the participant reports the initial sensation of pain. The pressure at which pain is first perceived is recorded as the PPT value, expressed in pounds per square inch (Ibf). In this study, PPT measurements were conducted at the site of maximal pain in the lumbar area, with two measurements taken at each assessment point and a one-minute interval between measurements to determine the average value [26, 27].

K-ODI

In this study, daily activities were assessed using the Korean Oswestry disability index (K-ODI) developed by Fairbank et al. [28] (1980) and modified and supplemented by C. Jeon et al. [29] to include pain level, walking, sitting, sleeping, standing, sleeping, social activities, and going out. The lower the total score of the nine items related to daily life behaviors was, the less problem participants had with daily life activities.

Data collection

This study was conducted after receiving approval from the E University Bioethics Committee (IRB NO. ewha-202110-0020-01). After seeking cooperation from the managers of four elderly welfare facilities in A city, B city, S city, and I city in Korea, a notice was posted in each facility to recruit participants. Subjects who voluntarily consented were given informed and written consent, and both researchers and subjects were required to strictly observe quarantine rules such as hand hygiene and wearing masks to prevent the spread of COVID-19.

The investigator directly applied the hand pressed-pellet therapy to the hands of the intervention group and placebo group participants for each study. This experiment was applied while the intervetion group and placebo group did not know which group they were assigned to. (single blined)There were no disadvantages to the participants who withdrew from the study. Furthermore, the hand pressed-pellet mediation is known as a safe measure with less pain and free from side effects. The contact number of the investigator was provided to the participants for any inquiry regarding discomfort or questions about the study.

Data analysis

The collected data were analyzed using IBM SPSS Statistics version 26.0.

The specific analysis method is as follows.

1.

The general characteristics and health-related characteristics of the intervention group and the placebo control group were analyzed with descriptive statistics using the mean, standard deviation, frequency, and percentage.

2.

The prior homogeneity of general characteristics and health-related characteristics between the intervention group and the placebo control group was analyzed by the independent t-test, Fisher’s exact test, and Chi-square test.

3.

The normality verification of the dependent variable (VAS, pain pressure threshold, K-ODI) before the intervention of the intervention group and the placebo control group was analyzed by the Shapiro-Wilk test, and a nonparametric statistical technique was used for the variable that did not follow the normal distribution.

4.

The intragroup and intergroup differences and changes over time of the outcome variables of the intervention group and the placebo control group were analyzed using generalized estimating equations, repeated measures ANOVA, Wilcoxon test, Mann–Whitney U test, paired t-test, and independent t-test.