שברי מאמץ
Case Study: Differential Diagnosis anterior shin pain
Matan sadot
tDPT program, The College of St. Scholastica
PTH 8725 Sec700: Differential Screening -Fall 2022
Dr. Kassia Garfield
November 27, 2022
Abstract:
Physiotherapists are required to use effective and excellent injury rehab management in the sports medicine field. Sports injuries are complex and multivariate, making it challenging to identify risk variables and their subtle and variable interactions.
In the context of the treatment and prevention of sports injuries, the purpose of this case report is to discuss the differential diagnosis, acute management, and rehabilitation of a case of a suspected tibial stress fracture in an athlete who participates in professional water polo.
The subject of this case study, a 19-year-old male water polo player, came to the physiotherapist (PT) with recent onset, first episode, bilateral, diffuse anterior shin discomfort. Differential diagnosis, acute care, rehabilitation, and treatment setting techniques are the topic being discussed.
Patient presentation:
The subject of this case report is a 19-year-old male water polo player who presented with bilateral anterior shin pain. The subject participated in the local team and ISRAEL national team. In addition, he started preparing for the IDF (Israeli defense forces), and his wish was joining to one of the elite units called the Israeli navy seals ("Shayetet 13"). Recently, the player has engaged in several CrossFit programs to get in shape for getting ready for the trial period before selection for the elite army unit and quitting water polo. He has primarily only trained for water polo and fitness in the pool for the past ten years. The athlete’s last year's new weekly training schedule is presented in the table:
Training Schedule | Activity |
Sun: | Water polo and running |
Mon: Tue: Wed: Thu: Fri: Sat: | Swimming and cross fit Water polo and gym Swimming and gym Water polo and Running Competition (game day) and rest Rest and running |
He complains of pain that starts as soon as he runs or jumps. The pain does not go away and does not get any better. He has recently been experiencing nighttime pain following intense training.
Initial examination revealed no important medical history besides congenital Hip Developmentally Dysplastic (DDH); according to Vaquero-Picado et al. (2019), Infants with DDH have improper hip joint development. The hip joint's "ball" and "socket" do not fit together tightly. Leg length inequality (legs that are different lengths) and abnormal walking or gait patterns are symptoms that may point to developmental dysplasia of the hip. Patients under the age of six months are treated using ultrasound. X-ray imaging is utilized once a child is six months old. In the clinic, patients will also undergo specific motions to test the stability of their hip joints—age and the degree of dysplasia influence the course of treatment. Treatment might include surgery, casting, and bracing.
Reports of non-mechanical symptoms such as night or resting pain occur only in the last week. The history of low back pain occurred in the previous year but went without professional treatment and only with self-stretches and strength—no altered sensation or muscular weakness, indicating no systemic or proximal lumbar issues were found.
Physical examination:
The assessment revealed moderate diffuse tenderness of Medio-posterior in the distal third of the tibia's left and right posterior aspect. The pain was reported with a simple numerical rating scale (SNRS) as 8/10 bilaterally on light palpation. The subject showed no signs of significant inflammation, his symptoms were local to the distal third of the tibia, and muscle length and resistance testing were unprovocative. Foot posture index (FPI) demonstrates a positive score indicated for bilateral pronated feet (Lee et al., 2015). The following anthropometric measurements were discovered: height of 1.81 meters, a weight of 81 kg, and an average BMI index of 24.4
Physical observation reveals bilateral hip external rotation posture and a high Beighton score of 7/9 on the hypermobility test (Russek, 1999)
As for all patients who started to run, I also checked The Navicular Drop Test (NDT), which was positive. This test determines the degree to which runners pronate their feet (Brody, 1990).
Screening points:
The most common cause of calf discomfort in athletes is medial tibial stress syndrome. However, other disorders, such as chronic exertional compartment syndrome, stress fractures, nerve entrapment, and popliteal artery entrapment syndrome, should also be considered. For most persistent lower leg pain reasons, conservative treatment is the standard therapy; occasionally, surgery may be required.
Table 2 indicates differential diagnoses of chronic lower leg pain in athletes. (Brewer & Gregory, 2011)
Examples | |
Vascular Bone/periosteum Muscle/tendon Nerve entrapment Infection Malignancy | Popliteal artery entrapment syndrome Endofibrotic disease (primarily external iliac artery) Popliteal artery aneurysm Cystic adventitial disease Peripheral arterial dissection Intermittent claudication Deep vein thrombosis Stress fracture (tibia, fibula) Medial tibial stress syndrome Metabolic bone disease Muscle strains Tendinopathy Chronic exertional compartment syndrome Peripheral neuropathies Lumbar radiculopathy Osteomyelitis Muscle or bone neoplasm |
Early chronic compartment syndrome (CECS) was tentatively ruled out since the symptoms were worse rather than better right after exercise and did not match the typical signs of muscle tightness, burning, or neurological problems. (Edmundsson et al., 2009)
CECS is a disorder that causes persistent pain episodes due to increased pressure in the fascial compartments (muscles and neurovascular systems connected by fascia and bone). The anterior compartment is usually implicated (45%), followed by the lateral, deep, and superficial compartments. 85% to 95% of the time, symptoms are bilateral.
CECS pathogenesis is complex, and it may involve static muscular compartments, normal or pathological muscle swelling with activity, abnormally thickened fascia, normal muscle hypertrophy in response to resistance training, or dynamic contraction patterns during gait. (Touliopolous & Hershman, 1999)
Popliteal artery entrapment syndrome (PAES) was not strongly suspected. PAES is an uncommon condition that may cause young athletes to discomfort in their legs. The popliteal artery, which passes through and behind the knee, is compressed due to the contraction of the calf muscles. During exercise, this reduces the amount of blood that flows to the calf and lower leg. (Baltopoulos et al., 2004)
Nerve entrapment syndromes - when a peripheral nerve becomes immobile, loses flexibility, or is squeezed by the tissues surrounding it, this condition is known as nerve entrapment. The pain seems neuropathic or neurogenic and may be either acute or chronic in its presentation if a nerve is pinched or compressed. The most common symptom is a burning sensation brought on by activity and made worse by more exercise. Additionally, patients may have localized motor and sensory symptoms. Nevertheless, nerve entrapment symptoms may not often appear with evident neurologic indicators such as motor weakness, sensory loss, or reflex changes; hence, diagnosis is sometimes delayed. The saphenous, common peroneal, and superficial peroneal nerves are the ones that are most often at risk for entrapment. (Flanigan & DiGiovanni, 2011)
Stress fractures - overuse injuries often seen in sports and recruits for the armed forces. The multifactorial etiology often includes repeated submaximal stressors. Stress fractures may also develop due to intrinsic causes, such as hormone abnormalities, particularly in women. The typical presentation is when a patient develops discomfort slowly over time after increasing their workout intensity. Although imaging techniques, including radiography, scintigraphy, computed tomography, and magnetic resonance imaging, may provide confirmation, the diagnosis is essentially clinical. The femoral neck (tension side), the patella, the anterior cortex of the tibia, the medial malleolus, the talus, the tarsal navicular, the fifth metatarsal, and the great toe sesamoids are specific locations for this kind of stress fracture (Fredericson et al., 2006).
Medial tibial stress syndrome (MTSS) – is a common reason for pain near the tibia bone in the front of the calf. The tibia is the prominent bone that supports body weight and transfers it to the calf region. It acts as a point of attachment for several muscles in walking and running. The pain will typically first appear in the lower third of the tibia bone, in the middle of the bone. The person will experience pressure from the splinter shin due to increased attraction of the bone shell (periosteum), which causes inflammation and pain. Literature categorizes this occurrence into anterior and posterior shin splints. (Story & Cymet, 2006)
Muscles are involved in the pain that radiates along the front of the tibia bone. "The collapse of the foot" (hyperpronation) increases torsion forces and strain on the tibia bone. It may occur due to weakness or insufficient muscles, including the tibialis anterior, posterior, and all other calf and foot intrinsic muscles. (Story & Cymet, 2006)
Moen et al. (2009) explain that the main factor in both pathologies is a continuous load brought on by shocks from the contact of the feet with the ground during activities like walking, jumping, running, and other physical endeavors that involve overworking the muscles and bones.
Main points (include suggested risk factors to rule out stress fracture)
(Changstrom et al., 2014)
1. Normal general health - no underlying medical conditions or metabolic or systemic disorders are known.
2. Mental state - He claims to have no stress or mental issues.
3. Nutrition - a balanced and healthy diet is reported.
4. Does not consume alcohol or smoke
5. report that he is not taking any medication - Glucocorticoids, anticonvulsants, antidepressants, methotrexate, antiretrovirals, and radiation therapy are some of the medications considered to be risk factors. (Boyce & Gafni, 2011)
6. There has been no history of fractures of any kind.
During the examination, general over-flexibility, including overextension in both knees and hyperpronation in the foot, were identified as risk factors for shin pain.
All ranges of motion and muscle tests were clean.
Red Flags:
Recent worsening, reports of non-mechanical symptoms such as night or rest pain.
At this point, I decided not to refer or ask the attending physician for an x-ray or imaging. It should be noted that this was a mistake in the therapeutic decision. According to Nye et al. (2020), serial radiographs may be recommended when bony soreness is present in the presence of 1 or more established risk factors, and there is no clinical indication of high-risk bone involvement.
Medial tibial stress syndrome is the chosen diagnosis for the intervention.
Goals of treatment:
1. First phase - pain inhibition management. within three or four weeks, a pain reduction from 8/10 during exercises or palpation to a pain level of 4/10
2 Returning gradually, within four weeks, to weight-bearing activities like running and jumping by the training schedule that was followed before the injury
3. the Main goal is 5 km of running at the selected speed (according to the IDF draft goals), Being able to finish strength training without feeling pain in six to eight weeks.
The treatment is six weeks and consists of several weekly sessions and an independent strengthening program.
There were several procedures carried out, including:
1. Setting expectations about the phenomenon and the anticipated recovery period.
2. Several pain-inhibition modalities include dry needling, electrotherapy, and manual therapy.
3. Creating and modifying a home-based, independently carried-out exercise program.
4. Strengthening and proprioception exercises in the clinic.
5. Tips for reducing the temporary exercise load.
Medication:
*The patient does not use any medication; this section is part of the pain management program.
There is a dilemma with using medications in any injury or involvement of musculoskeletal (MSK) disorders. Physiotherapists are not permitted to recommend medications in Israel, but this issue occurs in every intervention, so they must be aware of the benefits and disadvantages of every drug.
Drug therapy for musculoskeletal pain has changed significantly over the last ten years. The "Decade of the Musculoskeletal System" was declared by the World Health Organization a few years ago (Rao & Knaus, 2008). This announcement accelerated the understanding, diagnosis, and treatment of musculoskeletal pain, leading to the writing of numerous drug therapy guidelines that underwent significant changes over time. The use of non-steroidal anti-inflammatories (NSAIDs) for the treatment of pain, recommendations to switch to COX-2 inhibitors, and the use of paracetamol and later Opioids are all highlighted in a review of guidelines from a decade ago (Curatolo & Bogduk, 2001). The drug Vioxx (Rofecoxib) removed from the market due to an elevated risk of cardiovascular events has recently resulted in a significant change in treatment (Curatolo & Bogduk, 2001). The safety of most medications used to treat musculoskeletal pain has been extensively reviewed in the literature over the past few years, and additional medications—like those that contain propoxyphene—have been taken off the market.
The American Pain Society, the European League Against Rheumatism, and other professional associations all support paracetamol as a first-line treatment for musculoskeletal pain, including joint pain (Pendleton, 2000). The drug's high safety profile justifies the recommendation, even though its effectiveness in treating pain is marginally inferior to that of non-steroidal anti-inflammatories. Non-steroidal anti-inflammatories seem to have good efficacy for pain in the musculoskeletal system. However, they are less effective for more complicated conditions, like back pain with a nerve component, such as disc involvement or compression of the sciatic nerve (Koes et al., 1997).
The increased risk of gastrointestinal bleeding makes the safety profile of medications in this family problematic. Up to 16,500 people per year in the United States perish as a direct result of complications, primarily gastrointestinal bleeding, associated with the use of medications in this family, according to two sizable review articles published in 1999. Significantly fewer severe gastrointestinal complications have been reported due to the new medications in this family, which include selective COX-2 inhibitors. In a sizable study comparing the drug Vioxx to Naproxen, fewer gastrointestinal side effects were noticed in Vioxx users in patients with rheumatoid arthritis. (van Tulder et al., 2000)
*In this case study, the patient refused and was not advised to take any medication.
Patient Management and Outcome
Over a month and a half, there was a total of six different sessions that took place. Each treatment lasts forty minutes, and the total time spent practicing can last up to an hour and a half. Some treatments were modulations for pain reduction, as well as practice and guidance.
Dry needling was performed on the calf muscle and the tibialis (anterior and posterior) by the sensitive points that had been previously diagnosed. The needles of choice are made by Seirin and measure 0.4 mm x 30 mm.
Manual therapy: During each session, various treatments were performed, including techniques such as muscle energy, fascial manipulation (stecco), peripheral foot, and proximal tibia fibula joint manipulation. Soft tissue massages were included in all treatments as well.
Exercises: The most emphasis was placed on weight-bearing practices, including perturbations coming from several different directions, activities performed on unstable surfaces, and strengthening exercises using weights (with emphasis on lower extremity eccentric exercises)
Electrotherapy: After each session, a complex device for muscle recovery was applied along the front and back of the calf muscles.
Intervention result:
The pain reported with a simple numerical rating scale (SNRS) was 6/10 bilaterally on light palpation. The patient claims he cannot run for more than ten minutes without experiencing pain. While at rest, the pain persists. The nighttime pains come and go.
Medical intervention:
The physician's explanation and referral to an orthopedic surgeon were decided to continue after poor treatment results. The attending physician prescribed an X-ray and bone scintigraphy. At the same time, since bone scintigraphy appointments take a while, it was advised to abstain from all physical activity (running, jumping) until the investigation finishes.
Imaging referral:
Although MRI is the preferred imaging modality for adolescent athletes because of its early detection and absence of radiation, it is more expensive. Due to its high sensitivity, specificity, and ability to distinguish between stress fractures and other tissue abnormalities, MRI is attractive for the early detection of stress fractures (Hoffmeyer et al., 2012). According to the Ministry of Health's and healthcare providers' policies, an MRI appointment takes a long time and is not always employed for every case in Israel. There was no referral for an MRI.
Radiography - According to BATT et al. (1998), even though X-rays are neither the most accurate nor the Gold Standard for identifying stress fractures, it is the most widely used and affordable diagnostic tool for additional investigation. The acute phase of a stress fracture does not lend itself to radiography being a sensitive diagnostic imaging technique. A periosteal response may be seen on an X-ray three weeks after the incident, although a stress fracture may not be identified beyond the development of a callous.
Scintigraphy - A radioactive substance is injected into the blood during bone scintigraphy or a nuclear medicine bone scan to identify the gamma rays released in locations of elevated bone metabolism. It is acknowledged that bone scintigraphy is a susceptible method for stress fracture diagnosis. According to studies, diagnostic accuracy ranges from 74 to 92.9% sensitivity, 73.8% specificity, and 83.3% accuracy. However, non-ionizing radiation sources like magnetic resonance imaging have recently overtaken radioisotopes as the preferred imaging modality for adolescent athletes (MRI). (Hoffmeyer et al., 2012)
Result:
The results of the bone scintigraphy show that the right foot: Grade I: A stress fracture may be inferred from a small, ill-defined lesion with a little increase in cortical activity. Grade 2: well-defined, elongated lesion with substantially elevated cortical activity is seen in the left foot.
The findings of the tests indicate that a level 1 to 2 is present in the identification of stress fractures in the tibia. The decision was made to continue the physiotherapy treatment, including complete rest for eight weeks from impact activity, including jumping, running, and bouncing.
At the same time, aerobic exercise, which included swimming and water polo sports, was given the green light. In the treatment program, an emphasis was placed on continuing eccentric exercises to strengthen the foot muscles, aiming for foot pronation and alignment.
Discussion:
Stress fractures are a serious public health issue impacting athletes' ability to practice and compete. Several variables influence the frequency of stress fractures. However, it is unclear to what extent each factor influences the development of stress fractures in young athletes. Athletes that suffer from stress fractures miss training days and have difficulty competing. Stress fractures are localized thinning of the bone tissue that results from an activity that repeatedly applies focused loads to the skeleton; however, these loads are insufficient to result in actual fractures. Numerous disorders brought on by repeated and prolonged loads are included in the concept of stress fractures, also known as bone stress injury. Bone scintigraphy or other diagnostic techniques can detect stress fractures even when there are no symptoms. Athletes with stress fractures frequently experience pain, which prevents them from practicing or competing. The degree of severity determined by the imaging methods is only sometimes correlated with the intensity of the pain. According to the literature, stress fractures occur 10% more frequently among athletes than adults (0.8–19%). Teenagers in their adolescence are more susceptible to stress fractures than young adults, with the 15–19 age group having the highest prevalence of stress fractures. (Fredericson et al., 2006)
Swimmers have a higher rate of stress fractures than athletes who compete in sports where there is thought to be a stress fracture risk. Since swimming is a sport with little impact from load and body weight, there is a phenomenon of decreased bone mass among swimmers, and this is likely the main factor increasing their risk of stress fractures. (Gomez-Bruton et al., 2017)
According to Changstrom et al. (2014), the nature of training, less energy availability, origin (hereditary factors), a history of stress fractures, bone mass and density, sex, biomechanics, hormones, and different drugs are just a few of the factors that impact bones. It is unclear how widespread the stress fracture phenomenon is among them, and it varies from person to person.
Re-assessment and treatment results that fall short of expectations necessitate reconsidering and modifying a therapeutic course of action.
Prevention and treatment
Combining or switching to aerobic exercise with lighter loads, such as swimming, elliptical, and cycling, will reduce symptoms. These activities lessen the strain and shocks placed on the injury site and relieve pain.
Running volume must be carefully monitored as the rehabilitation phases advance, the patient gradually resumes running, and proper footwear must be worn at all times.
The work on strengthening and restoring the desired muscular balance will also start in treatments. This is done as part of the rehabilitation and the gradual return to the routine of activity and running. An imbalance between all calf and foot muscles contributes to the issue's development. Focusing the tibialis posterior, soleus, and tibialis anterior muscles exhibit an unsynchronized muscular attraction (RICE et al., 2019). The imbalance contributes to the development of pain by placing a heavy load on the tibia bone.
A key element of rehabilitation within physiotherapy is the emphasis on stabilizing appropriate muscles in the foot, around the calf, and in the lower limb. The patient's ability to resume optimal activity, including running in a quality manner and the likelihood that the injury will recur and manifest again will depend on the effectiveness of the rehabilitation.
Conclusions:
Medial tibial stress syndrome, exertional compartment syndrome, stress fractures, nerve entrapment, and popliteal artery entrapment syndrome is the conditions responsible for most cases of persistent calf discomfort in athletes. The combination and overlapping symptoms might make diagnosis and therapy challenging. It is essential to do a complete history and physical examination. The first therapy for most persistent lower leg pain cases is conservative management.
It is recommended that those with a low risk of stress fractures refrain from engaging in high-impact activities. A physiotherapist should be contacted to receive an accurate diagnosis, supportive care, preventive treatment, tools for practicing and maintaining therapeutic gains at home, and referral for a clear continuation as necessary.
References:
Baltopoulos, P., Filippou, D. K., & Sigala, F. (2004). Popliteal artery entrapment syndrome. Clinical Journal of Sports Medicine, 14(1), 8–12. https://doi.org/10.1097/00042752-200401000-00002
Batt, M. E., Ugalde, V., Anderson, M. W., & Shelton, D. K. (1998). A prospective controlled study of diagnostic imaging for acute shin splints. Medicine and science in sports and exercise, 30(11), 1564–1571. https://doi.org/10.1097/00005768-199811000-00002
Boyce, A. M., & Gafni, R. I. (2011). Approach to the child with fractures. The Journal of Clinical Endocrinology & Metabolism, 96(7), 1943–1952. https://doi.org/10.1210/jc.2010-2546
Brewer, R. B., & Gregory, A. J. (2011). Chronic lower leg pain in athletes. Sports Health: A Multidisciplinary Approach, 4(2), 121–127. https://doi.org/10.1177/1941738111426115
Brody, D. M. (1990). Evaluation of the injured runner. Techniques in Orthopaedics, 5(3), 16–17. https://doi.org/10.1097/00013611-199009000-00006
Changstrom, B. G., Brou, L., Khodaee, M., Braund, C., & Comstock, R. D. (2014). Epidemiology of Stress Fracture Injuries Among Us High School athletes, 2005-2006 through 2012-2013. The American Journal of Sports Medicine, 43(1), 26–33. https://doi.org/10.1177/0363546514562739
Curatolo, M., & Bogduk, N. (2001). Pharmacologic pain treatment of musculoskeletal disorders: Current perspectives and prospects. The Clinical Journal of Pain, 17(1), 25–32. https://doi.org/10.1097/00002508-200103000-00005
Edmundsson, D., Toolanen, G., Thornell, L.-E., & Stål, P. (2009). Evidence for low muscle capillary supply as a pathogenic factor in chronic compartment syndrome. Scandinavian Journal of Medicine & Science in Sports, 20(6), 805–813. https://doi.org/10.1111/j.1600-0838.2009.01013.x
Flanigan, R. M., & DiGiovanni, B. F. (2011). Peripheral nerve entrapments of the lower leg, ankle, and Foot. Foot and Ankle Clinics, 16(2), 255–274. https://doi.org/10.1016/j.fcl.2011.01.006
Fredericson, M., Jennings, F., Beaulieu, C., & Matheson, G. O. (2006). Stress fractures in athletes. Topics in Magnetic Resonance Imaging, 17(5), 309–325. https://doi.org/10.1097/rmr.0b013e3180421c8c
Frost, H. M. (1990). Skeletal structural adaptations to mechanical usage (SATMU): 1. redefining Wolff's law: The bone modeling problem. The Anatomical Record, 226(4), 403–413. https://doi.org/10.1002/ar.1092260402
Gomez-Bruton, A., Gonzalez-Aguero, A., Matute- Llorente, A., Gomez-Cabello, A., Casajus, J. A., & Vicente-Rodríguez, G. (2017). Longitudinal effects of swimming on bone in adolescents: A QCT and DXA Study. Biology of Sport, 34(4), 361–370. https://doi.org/10.5114/biolsport.2017.69824
Hoffmeyer, B., Ruf, J., Seidensticker, M., Steffen, I., Zarva, A., Fischbach, F., Wieners, G., Furth, C., Lohmann, C., Amthauer, H., & Dobrindt, O. (2012). MRI versus Bone Scintigraphy. Nuklearmedizin, 51(03), 88–94. https://doi.org/10.3413/nukmed-0448-11-12
Koes, B. W., Scholten, R. J., Mens, J. M., & Bouter, L. M. (1997). Efficacy of non-steroidal anti-inflammatory drugs for low back pain: A systematic review of randomized clinical trials. Annals of the Rheumatic Diseases, 56(4), 214–223. https://doi.org/10.1136/ard.56.4.214
Lee, J. S., Kim, K. B., Jeong, J. O., Kwon, N. Y., & Jeong, S. M. (2015). Correlation of foot posture index with plantar pressure and radiographic measurements in pediatric flatfoot. Annals of Rehabilitation Medicine, 39(1), 10. https://doi.org/10.5535/arm.2015.39.1.10
Moen, M. H., Tol, J. L., Weir, A., Steunebrink, M., & De Winter, T. C. (2009, July). Medial Tibial Stress Syndrome. Sports Medicine, 39(7), 523–546. https://doi.org/10.2165/00007256-200939070-00002
Pendleton, A. (2000). Eular recommendations for the management of knee osteoarthritis: Report of a task force of the Standing Committee for International Clinical Studies including therapeutic trials (ESCISIT). Annals of the Rheumatic Diseases, 59(12), 936–944. https://doi.org/10.1136/ard.59.12.936
Rao, P., & Knaus, E. E. (2008). Evolution of nonsteroidal anti-inflammatory drugs (NSAIDs): Cyclooxygenase (cox) inhibition and beyond. Journal of Pharmacy & Pharmaceutical Sciences, 11(2), 81. https://doi.org/10.18433/j3t886
Rice, H., Weir, G., Trudeau, M. B., Meardon, S., Derrick, T., & Hamill, J. (2019, May 16). Estimating Tibial Stress throughout a Treadmill Run. Medicine & Science in Sports & Exercise, 51(11), 2257–2264. https://doi.org/10.1249/mss.0000000000002039
Russek, L. N. (1999). Hypermobility syndrome. Physical Therapy, 79(6), 591–599. https://doi.org/10.1093/ptj/79.6.591
Story, J., & Cymet, T. C. (2006). Shin splints are painful to have and to treat. Comprehensive Therapy, 32(3), 192–195. https://doi.org/10.1007/s12019-006-0012-7
Touliopolous, S., & Hershman, E. B. (1999). Lower leg pain. Sports Medicine, 27(3), 193–204. https://doi.org/10.2165/00007256-199927030-00005
van Tulder, M. W., Scholten, R. J., Koes, B. W., & Deyo, R. A. (2000). Nonsteroidal anti-inflammatory drugs for low back pain. Spine, 25(19), 2501–2513. https://doi.org/10.1097/00007632-200010010-00013
Vaquero-Picado, A., González-Morán, G., Garay, E. G., & Moraleda, L. (2019). Developmental dysplasia of the hip: Update of Management. EFORT Open Reviews, 4(9), 548–556. https://doi.org/10.1302/2058-5241.4.180019