We present a protocol for using Fu’s subcutaneous needling for knee osteoarthritis pain, which combines swaying movement and reperfusion approach techniques. This protocol has great potential for future applications in myofascial pain treatment and could enhance Fu’s subcutaneous needling (FSN) manipulation skills.
Fu’s subcutaneous needling (FSN) is a new acupuncture and dry needling technique based on traditional Chinese medicine. It rapidly produces long-lasting effects in soft tissue injuries, particularly in painful musculoskeletal conditions, by providing stimulation primarily in the subcutaneous area. Osteoarthritis (OA) is the most common joint disease in adults worldwide and is often accompanied by a painful syndrome of structural changes in the peripheral joints of the knee. However, the etiology of OA pain is not fully understood, though myofascial trigger points (MTrPs) are commonly found in the lower limb muscles (so-called “tightened muscles”) of patients with knee OA.
FSN has been used in many fields for the treatment of acute pain problems and can relieve muscle contraction from MTrPs, thereby improving the local circulation. This study recruited patients with pain from knee OA into an FSN group or a transcutaneous electrical nerve stimulation (TENS) group with three treatment sessions and a follow-up over the course of 2 weeks. The results showed that FSN was effective in treating soft tissue pain around the knee with OA. This study aimed to establish and visualize three key technical indicators during FSN therapy, including the FSN needle insertion point and layer; the frequency and duration of the swaying movement; and the manipulation of the reperfusion approach. These findings have great potential for future applications in myofascial pain treatment, especially for pain management. Following this protocol could enhance FSN skills.
With the aging of the world's population, osteoarthritis (OA) has become one of the most common musculoskeletal disorders in the elderly1. OA is a chronic, localized joint disease, and the prevalence of OA varies between joints, with the knee being the most commonly affected joint2. The current global prevalence of degenerative joint disease of the knee, also known as knee OA is ~3.8%; indeed, the prevalence increased from 4.71 million in 2010 to 5.4 million in 2020, and it may possibly increase to 6.4 million by 20353. The diagnosis of knee OA is primarily defined by pathology, radiology, and clinical symptoms4. Most research in the treatment and diagnosis of knee OA has focused on surgical or pharmacological strategies5. However, joint degeneration involves the cartilage and many surrounding tissues, including the meniscus, subchondral bone, synovium, joint capsule, ligaments, and muscles6. Radiographic imaging and clinical symptoms are often used to determine the stage of knee degeneration and are commonly used as the main basis for diagnosis7. Radiographic findings focus on the narrowing of the joint space, the presence of osteophytes, subchondral sclerosis, and cysts8, while clinical signs include pain, stiffness, swelling, or a feeling of pressure9. The radiographic features of OA are often weakly associated with clinical symptoms10. Some researchers have postulated that the muscles have a significant role in the development of degenerative knee OA11. Among them, the skeletal muscle structure and function are thought to be involved in the development and progression of OA disease in the knee12. Many people with knee OA do not wish to undergo surgery, and most knee patients in primary care in particular have a preference for non-surgical treatment13. As a result, the treatment of degenerative knee OA by treating the skeletal muscles has been of increasing interest to clinicians over the past few years.
The non-surgical treatment of knee OA can be quite challenging, with pain and joint stiffness being the main complaints expressed by patients seeking clinical intervention3. A number of conservative approaches to pain management have been tested, including changes to daily activities and various physiotherapy techniques, but the best approach is still under debate14,15. A preliminary study investigated the association between myofascial trigger points (MTrPs), pain, and function in patients with bilateral knee OA and demonstrated that more active MTrPs are associated with greater persistent pain and reduced physical function16. Therefore, the authors hypothesize that MTrP in the lower limb muscles may be an important source of pain and stiffness in patients with knee OA.
Fu's subcutaneous needling (FSN) is an innovative acupuncture therapy based on acupuncture and traditional Chinese medicine models, and it was developed by the traditional Chinese medicine practitioner Zhonghua Fu17. Recent studies have shown that FSN has a positive effect on the treatment of pain control in musculoskeletal diseases, such as lateral epicondylalgia18, low back pain19, and chronic neck pain20, without adverse side effects18,19,20. The theory of affected muscles (so-called pathological "tightened muscles", with one or more MTrPs in the muscle) in FSN suggests that functional changes in muscles are an important cause of pain and dysfunction in knee joints21. The clinical application of FSN over the past 20 years has led to an increasing refinement of the operational technique and clinical theory; however, there are still no reports or video demonstrations on the detailed treatment of pain caused by various muscle disorders, such as knee OA, with respect to the clinical detection of MTrPs, the identification of the FSN insertion area, and the reperfusion approach techniques as standardized clinical trial practices.
To accelerate the standardization of FSN treatment and facilitate the choice of techniques for future FSN-related clinical studies, this study uses a standardized model for the measurement of the MTrP location, the needle insertion point, the number of swaying movements, and the assessment of the reperfusion approach techniques for knee OA, with transcutaneous electrical nerve stimulation (TENS) treatment as the control group. The protocol aims to provide a more complete technical solution for the analysis of FSN therapy to facilitate future studies.
The procedures presented below were approved by the Research Ethics Committee of China Medical University & Hospital, Taichung, Taiwan (CMUH107-REC3-027) and registered at the ClinicalTrials.gov Protocol Registration and Results System (registration number NCT04356651). All patients had to provide their written informed consent before participating in this clinical trial. This experimental protocol illustrates a typical FSN manipulation for use in a laboratory or clinical setting.
1. Recruitment of patients with degenerative knee OA
2. Treatment groups
3. Implementation of the FSN manipulation (Figure 1)
NOTE: Although FSN has its origins in traditional acupuncture, the actual procedure is very different. The procedure of FSN treatment is strictly standardized according to the procedures proposed by the developer of the technique. The main emphasis is on the identification of tightened muscles, the selection of the needle insertion points, the swaying movement, and the reperfusion approach.
4. Implementation of the TENS manipulation
NOTE: TENS is a non-invasive physiotherapy modality that is commonly used to treat acute and chronic pain caused by a variety of conditions. The procedure for TENS treatment emphasizes the patch position selection, current direction selection, and current frequency adjustment.
5. Post-intervention and follow-up outcome assessments
NOTE: The entire experiment course lasted 2 weeks. In this trial, a total of three treatment sessions were administered in the first week, with assessments before and immediately after each session, and follow-up visits were conducted in the subsequent weeks 1 and 2. Outcome measurements, which included the pain qualities, the muscle and tendon qualities, and the functional index questionnaire assessment were used.
6. Statistics
The described protocol was implemented in a clinical setting at the China Medical University Hospital of Taiwan, and its feasibility and outcomes were assessed in a recently published clinical study25. The study enrolled a total of 31 participants (10 males, 21 females) to complete the intervention. The FSN group consisted of 15 participants (4 males, 11 females, mean age: 65.73 years ± 6.79 years), while the TENS group consisted of 16 participants (6 males, 10 females, mean age: 62.81 years ± 5.72 years) (Table 1). The results of the study showed that the FSN group exhibited a significant improvement in pain characteristics as measured by the VAS (p < 0.05) (Table 2). The study also revealed a significant difference in the PPT of the quadriceps muscle in the FSN group (p < 0.05), indicating an improvement in the muscle and tendon qualities, and this was particularly noticeable among the participants who received immediate treatment (Table 3). The functional index questionnaire assessment revealed that the FSN group demonstrated significant enhancements in the WOMAC and Lequesne index scores, reflecting improvements in physical function, pain, and stiffness. The improvements were noticeable in the immediate, 1 week, and 2 week follow-up periods (p < 0.05) (Table 4). The findings of this study provide evidence to support the feasibility of FSN therapy as a treatment option for patients suffering from painful knee OA. The results also establish the effectiveness of FSN treatment in alleviating the soft-tissue pain associated with knee OA caused by MTrPs (Figure 5).
Figure 1: Structure of the Fu's subcutaneous needling needle. (A) FSN-inserting device with a FSN needle. (B) The FSN needle is made up of three parts: a solid steel needle core with a needle base (bottom), a soft tube (middle), and a protection sheath (top). Abbreviation: FSN = Fu's subcutaneous needling. Please click here to view a larger version of this figure.
Figure 2: Manipulations of the Fu's subcutaneous needling needle. (A) The way of holding the inserting device. (B) The method to insert the FSN needle into the skin-the needle tip is placed at approximately 15° to the skin. (C) The method to separate the FSN needle from the inserting device. (D) Locating the insertion point, which is at the proximal one-third of the line from the anterior superior iliac spine to the superior border of the patella. Abbreviation: FSN = Fu's subcutaneous needling. Please click here to view a larger version of this figure.
Figure 3: Fu's subcutaneous needling manipulations of the participants' limbs. (A) The holding of the FSN needle while performing the swaying movement. Using the thumb as the fulcrum, the middle finger and thumb affix the needle in a face-to-face manner, with the index and ring fingers moving back and forth. (B) Reperfusion approach with the participant performing a dorsiflexion movement and the physician performing an antagonistic movement with opposing dorsiflexion forces. (C) Reperfusion approach with the participant actively moving the relevant muscles and joints during dorsiflexion from the starting position. (D) Reperfusion approach with the participant actively performing knee flexion with the physician's resistance. (E) Reperfusion approach with the participant performing active knee extension against the physician's resistance. Abbreviation: FSN = Fu's subcutaneous needling. Please click here to view a larger version of this figure.
Figure 4: Positioning of the transcutaneous electrical nerve stimulation pads. TENS pads were attached at ST34, GB34, SP10, and SP9; the pads were placed in a cross pattern to treat the pain associated with knee osteoarthritis. Abbreviation: TENS = transcutaneous electrical nerve stimulation. Please click here to view a larger version of this figure.
Figure 5: Comparison between the Fu's subcutaneous needling and transcutaneous electrical nerve stimulation groups. (A) The pre- and post-treatment values of the VAS. (B) The pre- and post-treatment values of the PPT for the quadriceps muscle. (C) Comparison of the WOMAC between the two groups after each treatment. (D) Comparison of the Lequesne index between the two groups after each treatment. * Represents the FSN group, p < 0.05; # represents the TENS group, p < 0.05. Abbreviations: VAS = visual analog scale; PPT = pressure pain threshold; WOMAC = Western Ontario and McMaster Universities Arthritis Index; Tx = treatment; FSN = Fu's subcutaneous needling; TENS = transcutaneous electrical nerve stimulation. Please click here to view a larger version of this figure.
Table 1: Baseline characteristics and clinical evaluation indicators of the participants. Data are expressed as mean ± SD; the P values were obtained from analyses with independent samples t-tests. This table is from Chiu et al.25. Abbreviations: FSN = Fu's subcutaneous needling; TENS = transcutaneous electrical nerve stimulation; VAS = visual analog scale; WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index; PPT = pain pressure threshold; ROM = range of motion. Please click here to download this Table.
Table 2: Pain qualities compared between the FSN and TENS groups. Data are expressed as mean ± SD. This table is from Chiu et al.25. Abbreviations: FNS = Fu's subcutaneous needling; TENS = transcutaneous electrical nerve stimulations; VAS = visual analog scale; tx = treatment; F/U = follow-up. * Indicates a significant difference, as analyzed by a paired t-test. Please click here to download this Table.
Table 3: Muscle and tendon qualities (PPT of the quadriceps muscle) compared between the FSN and TENS groups. Data are expressed as mean ± SD. This table is from Chiu et al.25. Abbreviations: FNS = Fu's subcutaneous needling; TENS = transcutaneous electrical nerve stimulations; PPT = pain pressure threshold; tx = treatment; F/U = follow-up. * Indicates a significant difference, as analyzed by a paired t-test. Please click here to download this Table.
Table 4: WOMAC and Lequesne index compared between the FSN and TENS groups. Data are expressed as mean ± SD. This table is from Chiu et al.25. Abbreviations: FNS = Fu's subcutaneous needling; TENS = transcutaneous electrical nerve stimulations; WOMAC = Western Ontario and McMaster Universities Arthritis Index; tx = treatment; F/U = follow-up. * Indicates a significant difference, as analyzed by a paired t-test. Please click here to download this Table.
The main findings of this study are as follows: (1) confirmation of the approach and complete procedure of the FSN treatment of knee OA; and (2) assessment of the improvement from before to after FSN treatment using a standardized assessment approach. Unlike traditional acupuncture and dry needling, FSN requires different forms of movement for clinical treatment, such as swaying movement and the reperfusion approach. The presence of multiple MTrPs, particularly the active and latent MTrPs, can often be a problem for new practitioners in choosing where to insert the needle. In addition, the evaluation of the post-treatment efficacy is also a major problem for FSN therapy, as in the past, it was mostly limited to the subjective descriptions of patients without objective data to evaluate the methods and practices. For these reasons, it has been difficult to standardize the use of FSN in the treatment of disease.
This is the first protocol to use the full procedure of treating degenerative knee OA with FSN and to define a protocol for assessing the improvement in the knee joint from before to after treatment. Knee joint kinematics are complex, as they comprise six degrees of freedom, including flexion/extension, adduction/abduction, and internal/external rotation; therefore, degeneration of the knee joint can seriously affect daily activities26,27. There is growing recognition that improving the health of skeletal muscles can have significant benefits for people with knee OA. Previous studies have shown that pain relief is the main benefit of FSN19, and the most significant and positive correlates of FSN therapy are pain inhibition and increased joint mobility.
FSN therapy has a unique approach; ignoring these differences between FSN and traditional acupuncture can compromise the effectiveness of the treatment. The needling insertion points of FSN are very different from the acupuncture points of traditional acupuncture. The insertion point in FSN is chosen based on a search for the corresponding tightened muscle based on pain (with one or more MTrPs in the muscle) after the treatment area has been determined. Throughout the experiment, there are a number of key steps that affect the results of the analysis. The most important treatment choice in FSN therapy is the selection of the tightened muscle; indeed, MTrPs are considered as a potential new target for therapeutic interventions aimed at treating idiopathic knee OA28. Travell and Simons identified the rectus femoris, vastus medialis, and vastus lateralis muscles as possible sources of MTrPs in people with knee OA29. Henry et al.30 evaluated myofascial pain in total knee replacement patients and concluded that the gastrocnemius and medial femoral muscles had the most MTrPs in their study. In this study, we pre-assessed three muscle segments: the quadriceps muscle, pes anserinus, and gastrocnemius muscle, with the quadriceps muscle being the final muscle chosen as the FSN insertion area. Our selection of the tightened muscle for treatment was similar to that in previous studies, as weakness in the quadriceps is often considered to be the cause of knee OA and is one of the earliest and most common findings in patients with knee OA31. Previous studies have reported that the sensation of knee pain is associated with weakness in the strength of the quadriceps, as muscle control is related to proprioceptive function32,33. Therefore, using FSN to treat the quadriceps in patients with degenerative knee OA could be a clinical priority in the future.
The FSN technique emphasizes the need to avoid soreness, numbness, and pain at the angle of insertion, which is important in order to avoid needle penetration of the vessel wall. In addition, the swaying movement is an important needle technique in FSN therapy, which involves traction on the subcutaneous tissue. The standardized definition of this technique in this paper makes it clearer and simpler for beginners to perform FSN therapy. The reperfusion approach is a complementary method in the process of FSN operation. In FSN therapy, the action of reperfusion forces the affected muscle to contract centripetally or centrifugally so that the local or peripheral arterial pressure of the tightened muscle increases, followed by rapidly stretching the tightened muscle. The reperfusion approach technique is usually used while the clinician performs the swaying movement with the right hand and uses the left hand to facilitate the localized movement of the patient’s limbs or uses the left hand or other body parts to facilitate the rhythmic movement of the relevant muscle that is contracting. Although the efficacy of the FSN can be rapidly increased and its adaptability to the specific disease enhanced when the reperfusion approach technique and swaying movement are used simultaneously, this makes the operator’s handling of the process more difficult. Through this video protocol, we help students and young practitioners improve their performance of the complex hand movements required for FSN manipulation. Through simple and efficient preparation, a standardized FSN practice can be followed.
The development of this method opens up a new standardized definition of FSN therapy for the treatment of various muscle disorders, and the protocol is considered to be feasible, acceptable, and safe. In the future, the standardized procedure can be employed to provide more data for clinical applications, education, and the application of this procedure to other pain-related disorders and can be used to provide visualized motor learning in FSN education and clinical trials.
The authors have nothing to disclose.
This study was supported by a grant from the China Medical University Hospital (DMR-109-095) and Asia University Hospital (10951025).
Fu’s subcutaneous needling | Nanjing Paifu Medical Science and Technology Co. | FSN needles are designed for single use. The FSN needle is made up of three parts: a solid steel needle core (bottom), a soft casing pipe (middle), and a protecting sheath (top). | |
Tissue Hardness Meter/Algometer Combo | ITO Co. | OE-220 | Uses a dedicated measuring device to convert muscle force into a numerical value. Allows objective evaluations of muscle force and eliminates problems of subjective assessments. |
Transcutaneous Electrical Nerve Stimulation | Well-Life Healthcare Co. | Model Number 2205A | Digital unit which offers TENS. Supplied complete with patient leads, self-adhesive electrodes, 3 AAA batteries and instructions in a soft carry bag. Interval ON time 1 – 30 s. Interval OFF time 1 – 30 s. |