Knee Myofascial Pain and Knee-Abdomen Syndromes; A Newly Identified Knee Disorders, Commonly Misdiagnosed as Arthritis, Multiple Case Study

Background: Knee osteoarthritis is a common orthopedic condition. Imaging based pathoanatomical findings are utilized as a cornerstone for diagnosis of the condition, 97% of asymptomatic knees demonstrate pathoanatomical findings, causing doubt of diagnosis and efficiency of intervention based on asymptomatically present pathoanatomical features. Purpose: This study explores myofascial dysfunctions as an alternative explanation to knee pain. Identifying new syndromes termed as knee myofascial pain and knee-abdomen syndromes. Therapeutic intervention: Describing 3 cases of knee osteoarthritis and one case of rheumatoid arthritis treated to full recovery as myofascial dysfunction. All of these cases were investigated and treated to complete recovery from specific myofascial continuity known as deep front line dysfunction, as a cause of knee pain. Results: Both syndromes demonstrated 50% to 100% pain reduction after one session of myofascial release, with no recurrence over long-term follow-up after discharge. Conclusion: Knee myofascial pain and knee-abdomen syndromes are clinically present commonly misdiagnosed as arthritic changes. Myofascial release produced an immediate major pain reduction ranging from 50 to 100%. High quality research is required to identify more accurate diagnostic criteria and consequently best treatment strategies.

Fascia as a part of the musculoskeletal (MSK) system has the potential to cause pain, dysfunction and disorders [29][30][31][32][33][34] . A multitude of techniques have been created & utilized by clinicians over the last century targeting this structure [35][36][37][38][39][40] . Fascia remains one of the least studied components of the MSK system. Lack of research regarding myofascial continuities and dysfunction exists, As many anatomists stated that anatomical description has been completed and no new knowledge is to be expected, causing a gradual reduction of budgets and research of anatomy [41] . A systematic review of 2016 investigated existence of myofascial lines presented by Tomas Myers in his book (Anatomy trains), concluded that most muscles are connected directly by connective tissue, with evidence regarding the existence of specific myofascial continuities that he termed the superficial back line (SBL), back functional line, and front functional line, these findings can provide a better understanding of musculoskeletal pain and dysfunction development, with a major need for further research [42] .
Deep front line (DFL) is a myofascial continuity described in the structural integration text of anatomy trains; authored by Tomas Myers [43] , Myers identified an anatomical connection between the knee capsule and the abdominal structure through the adductor muscle, medial & posterior intramuscular septa of the thigh, and Iliopsoas muscle, with its two parts, iliacus and psoas major [43] . An explanation of distant structure mutual influence is provided through Biotensegrity [43,44] , which is the transmission of a force between connected structures regardless of proximity.
Biotensegrity concept has been studied on the myofascial continuity of the plantar fascia, calf, hamstring and paraspinals, known as the superficial back line [43] , with therapeutic based evidence regarding the practical application of Biotensegrity was established, when myofascial release (MFR) was performed on the plantar fascia, an immediate increase of lumbar and hip range of motion was achieved [45] , while shortening of calf and hamstring was proven to be associated with plantar fasciitis [46][47][48] . Treatments based on the SBL myofascial continuities was advocated by Myers, and proven effective by research, as stretching of elements of the SBL; the calf and hamstring is determined as an effective treatment for plantar fasciitis [49][50][51] , surgical release of Proximal Medial Gastrocnemius was effective too [52,53] .
One issue hindering research and clinical development of manual techniques is descriptive terminology / Nomenclature. Many terms are used within each profession providing manual therapy, as Physical therapy, chiropractic, osteopathy, and others. These techniques are similar linguistically, even though they are indicating different & diverse techniques, & theoretical frameworks. This issue led to attempts to unify inter-professions research in spinal manipulation [54] . Fascial/myofascial release or manipulation are used interchangeably between clinicians and researchers, with no unification attempts produced yet, hence this paper, uses the term of "myofascial release" to indicate any technique or research regrading either fascial or myofascial manual treatment, while specifying in great details the techniques utilized in treating the presented case studies.
Myofascial release was effective clinically in a multitude of studies of fibromyalgia [55,56] , cervical spine dysfunction [57] , patellar tendinopathy [58] , pubescent postural hyperkyphosis [59] , systemic lupus erythematous [60] , rotator cuff tear [61] , Spastic Cerebral Palsy [62] . Even more effective than some standardized physical therapy in cases of low back pain [63] . MFR also positively affects the autonomic nervous system's parasympathetic activity with an increase in vagal tone [64,65] . An increase in parasympathetic activity can explain the psychological effects of MFR, as improvement of state-trait anxiety [66] , and anxiety and depression in fibromyalgia patients [55] . Evidence regarding MFR structural integration is lacking quantity because of small sample size and lack of control of some studies [67] . This paper present 3 cases that have been encountered with knee pain and medical diagnosis of knee OA and one case of rheumatoid arthritis (RA). All of these cases were investigated and treated to complete recovery from specific myofascial continuity known as deep front line dysfunction, as the cause of knee pain.
Myofascial release was the primary treatment applied to the accessible structure of the patients' DFL, through Myers's MFR techniques of DFL. MFR in its simplest form targeted restoration of mobility of myofascial and fascial layers from within, and with the surrounding structure. MFR techniques utilized with the cases included four variations of application: 1. Muscle was stroked in a longitudinal slow manner, aiming to mobilize fascia over muscles or fascial layers over each other. Which will be referred to as passive release. 2. Separation force applied perpendicularly through a parallel myofascial structure to restore mobility and separation between them. Which will be referred to as separation technique. 3. Force was applied to the myofascial structure while the muscle contracts, aiming to immobilize fascia while muscle contracts and mobilize below it. Which will be referred to as active release. 4. Special form in which combination of the previous is utilized.
The DFL includes the following structures which MFR was targeted to each, tibialis  [43] . Home exercise program consisted of self-stretching of hip adductors, and strengthening of antagonistic muscles of the hip flexors and adductors, specifically the gluteus maximus and medius, to utilize reciprocal control of the tight muscles of the DFL, as advocated by Janda [68] , noting that most of the patients became pain free after the first session of MFR, before performing stretching or strengthening exercises, that's utilized as a home exercise program. Utilized MFR techniques are demonstrated on volunteer subject, that provided consent for publication.         Case Study 2 63 years old female patient complains of unilateral knee pain with a history of C-section delivery. Patient complains of exacerbated knee pain after stepping into a hole on the beach, patient had knee pain for 20 years, diagnosed as knee OA, modified to OA & meniscal injury after the steppage incidence. Patient's pain was 8/10 NRS, exacerbated with weightbearing flexion as squatting or going upstairs. Patient demonstrated touch provoked pain over all components of DFL especially hip adductors when compared to other muscle groups. Patient underwent two treatment sessions of MFR to the DFL. Post 1st session pain was reduced to 2/10 during rest, patient was prescribed a home exercise program (HEP) of strengthening to weak gluteus medius and maximus, and quadriceps, and stretching of hip adductors. 2nd session was 10 days later. Post 2st session     Directly after MFR pain reached 0/10 of non-weight-bearing and 3/10 in weight-bearing with inability to perform full knee extension, exercise did not alter pain levels. Patient was prescribed HEP of strengthening exercise to the forementioned muscle, stretch to hip's adductors and heel prop to increase knee extension. After 4 session of MFR and strengthening HEP patient achieved 0/10 nonweight and weight-bearing, pain increased with standing or walking over 15 minutes, and reduced with rest and medications, the same medication was reported to have a much lesser effect on pain before. With no improvement in knee extension. As pain was controlled 5th session targeted increase of knee's extension range of motion (ROM) with mobilization and stretching exercise, pain levels increased with mobilization to reach 6 /10 of non-weightbearing and 8/10 in weight-bearing. The 6th session included MFR targeting pain reduction, which caused 0/10 pain outcome, also introduced balance exercises. The following 5 sessions alternated between increasing ROM & reducing pain. After 11 sessions pt achieved 0/10 either in non-weight or weight-bearing with full knee extension range of motion. Pain occurs after hour of standing or walking. Knee pain had not prevented sleep over the last 2 weeks of therapy. Patient was discharged from PT as no further improvement has been achieved, with an advice of lifetime maintenance of her prescribed HEP. 3 months follow-up revealed no regression of the case or reappearance of pain. Patient's low back pain reduction was also reported.
Patient received physical therapy before with pain improvement that never reached 0/10 or complete knee extension, and NSAIDs had minimal effect on pain. By contacting her previous physical therapists, knee joint mobilization and exercise were too painful and performed withing tolerance but still knee extension was never achieved. By the 4th month after discharge patient reported to the physical therapy clinic with reappearance of knee pain with limitation of knee extension. Patient had one month of vacation when she stopped her HEP, after 2 weeks of cessation of HEP pain reappeared and progressed rapidly, by the time of this article was written patient restarted Physical Therapy with pain of 8/10 during standing. Post one session patient pain reduced to 4/10 with improved knee extension, and she'll continue receiving the same previous treatment.

Discussion
All presented cases demonstrated major pain reduction on NRS ranging from 50% to 100% after one treatment. Case 1 demonstrated tenderness to C-section scar line, & complete resolution of pain from MFR with no need for further treatment or HEP. Cases 2 and 4 required more than one treatment session with concomitant muscle imbalance that required directed exercise. All of the 4 cases are termed to have knee myofascial pain syndrome, while case 1 had a sub-classification of knee myofascial pain syndrome to be termed knee-abdomen syndrome, as knee pain's primary cause is abdominal fascia incision of C-section through DFL.
All patients demonstrated touch provoked pain over all components of DFL when compared to other muscle groups, especially hip adductors, this pain was not identified by the patient until touch provoked it. This finding is the only present symptom of both syndromes, that to can be used diagnostically prior to MFR, the only sure sign is major pain reduction following MFR.
The four presented cases are representations of different patterns of knee pain of myofascial origin. In case 1 deep front line dysfunction (DFLD) was a standalone dysfunction, while in cases 2 and3 DFLD was associated with muscle imbalance, & in case 4 was associated with muscle imbalance and RA. The three recurring patterns are observed repeatedly clinically, as the most common pattern is DFLD with muscle imbalance especially weakness of gluteus medius and maximus, and quadriceps. Weakness of the gluteus medius and maximus can be attributed to tightness inhibition relation [68] , as tightness of specific muscle can reciprocally inhibit its antagonist and vice versa. Whether tightness of adductors or iliopsoas muscles caused weakness of gluteus medius and maximus, or weakness of the muscles caused tightness and dysfunction of the DFL is unknown to the authors. Sound clinical judgment requires managing both components as patient's treatment, whether one treatment of exercise alone or MFR alone well be enough to treat patients to full recovery is unknown & untested.
The second identified pattern is less common & encountered only twice by the authors, in which DFLD rises as a complication to C-section, & treated to 0/10 NRS within one session. The third pattern coexistence of DFLD and muscle imbalance with RA, in which treatment was required to all three components. Medications for RA with MFR and exercise.
Within the three presented patterns, standalone DFLD required minimal duration treatment of MFR alone, demonstrating immediate and long last recovery with no need for further treatment. DFLD with muscle imbalance required combined treatment with multiple sessions & HEP. After the disappearance of pain and normalization of muscle strength pain did not recure during long-term follow-up. The third pattern of DFLD with muscle imbalance and RA demonstrated slowest recovery rate with recurrence of symptoms with cessation of physical activity and HEP.
This scientific paper represents a general call to the biomedical community to start a widespread research of the presented syndromes and the most efficient and effective treatment strategies, and subsequent changes to OA diagnostic criteria, as well as generation of diagnostic criteria for knee-abdomen and knee myofascial pain syndromes.

Conclusions
Knee myofascial pain syndrome and knee-abdomen syndrome are newly identified causes of knee pain usually misdiagnosed as knee OA or arthritic changes. Knee-abdomen syndrome demonstrated complete resolution after one treatment session with no recurrence over long-term follow-up and is defined as DFL myofascial dysfunction with a direct cause of abdominal fascia incision. Knee myofascial pain syndrome is a DFL myofascial dysfunction associated with muscle imbalance that required addition of therapeutic exercises to MFR, with multiple sessions of treatment. Both syndromes demonstrated 50% to 100% pain reduction after one session of MFR, with no recurrence over long-term follow-up after discharge, unless another active cause was present as RA. Patients demonstration of touch provoked pain over components of DFL is the only present symptom of both syndromes, that can be used diagnostically prior to MFR. High quality research is required to identify more accurate diagnostic criteria and best treatment strategies.

Ethics approval and consent to participate
The presented cases were not preplanned as a clinical study. This paper represents reporting of clinical cases suspected & treated as myofascial dysfunction; hence no ethical committee approval was sought. Each case had an explanation regarding possibility of myofascial dysfunction contributing to her Knee pain, and verbal consent were given prior to MFR

Conflicts of Interest
The authors declare that there is no conflict of interest regarding the publication of this paper