AN IMAGING OVERVIEW

– Written by Carles Pedret, Spain, Stefano Palermi, Italy, Sandra Mechó, Spain, Gulraiz Ahmad, UK, and Justin C. Lee, UK

INTRODUCTION

Calf injuries are among the most common musculoskeletal injuries in sports, particularly affecting amateur athletes due to their frequent engagement in activities requiring explosive lower-limb movements¹.

These injuries often involve the triceps surae complex, a key functional unit comprising the medial and lateral gastrocnemius, the soleus, and their distal extension into the Achilles tendon. Understanding the anatomical structures and their interplay is critical for accurate diagnosis, effective management, and minimizing the time to return to play (RTP)

Accurate and early diagnosis is fundamental to optimizing outcomes in calf injuries. While ultrasound (US) is a widely used and accessible first-line imaging modality (especially when diagnosing injuries to the medial gastrocnemius and the plantaris in the calf, yielding exceptional diagnostic outcomes^2,3), it has limitations in evaluating deeper structures like the soleus muscle. In such cases, magnetic resonance imaging (MRI) serves as the gold standard⁴.

However, despite advancements in imaging techniques, a standardized approach to prognosis and management—particularly for soleus injuries—remains elusive due to the complex anatomy and variability in injury patterns^5–7.

This article provides a comprehensive, evidence-based overview of calf injuries, emphasizing anatomical variability, clinical presentation, imaging techniques, and management strategies. By integrating clinical and imaging insights, the aim is to equip clinicians with practical tools to improve diagnosis, streamline treatment, and facilitate a safe return to sports

TRICEPS SURAE COMPLEX ANATOMY

The triceps surae complex is a robust anatomical structure composed of three muscles: the medial and lateral heads of the gastrocnemius (superficial) and the soleus (deep). These muscles converge distally to form the Achilles tendon (AT), a critical structure for lower-limb biomechanics. Together, they reside in the posterior compartment of the lower leg, playing a central role in ankle plantarflexion and lower-limb propulsion during activities like running and jumping.

Gastrocnemius

The gastrocnemius muscle originates from the femoral condyles and merges into a broad connective tissue structure, the gastrocnemius aponeurosis (GA). Proximally, the GA is closely associated with, but not fused to, the posterior aponeurosis of the soleus (SA). Distally, these two aponeuroses fuse to form the Achilles tendon. (Figure 1)^8,9. The GA and SA are broad and flattened myoconnective structures and the AT exhibits a proximal flattened shape, maintaining an attachment to the deeper soleus muscle belly⁹. Distally, the AT has an extramuscular, elliptical morphology before its enthesial attachment into the calcaneus. The fusion region between the GA and SA exhibits considerable variability⁸.

A unique feature of the gastrocnemius is the “free gastrocnemius aponeurosis” (FGA), a distal segment devoid of muscle fibres, which contributes to the variability of injury patterns in this muscle⁸.

In summary, there are three anatomical regions within the medial gastrocnemius (MG) muscle-tendon continuum where injuries may occur:

• the MG distal myotendinous junction (located between the muscle belly and the gastrocnemius aponeurosis)
• the GA
• the FGA

Soleus

The soleus muscle originates from the posterior tibia, fibula, and the adjacent interosseous membrane. Its architecture is distinct, with a predominance of slow-twitch (type I) muscle fibres, making it essential for postural stability and endurance activities. The soleus comprises several connective tissue structures, including the medial and lateral aponeuroses (MA and LA) and a central tendon (CT) that extends distally into the AT¹⁰. The AT attaches to the posterosuperior region of the calcaneus, enabling the gastrocnemius-soleus muscle unit to facilitate ankle plantarflexion functionally¹¹.

The proximal tendinous arch, a connective tissue bridge, adds further complexity and variability to its anatomy. Unlike the gastrocnemius, the soleus demonstrates significant anatomical variability, particularly in the orientation and length of its aponeuroses and central tendon. This variability influences the biomechanics of the muscle and has implications for the prognosis and management of soleus injuries^10,12.

Two primary factors distinguish the anatomy of soleus muscles:

1. The existence or nonexistence of aponeuroses and connective tissue, their length and positioning, along with all potential combinations (Figure 2)
2. The orientation and pennation angles of the muscle fibres influenced by this anatomical variability.

These considerations are of paramount importance when planning a return to play (RTP)¹².

The triceps surae complex functions as a unified unit during plantarflexion, with each muscle contributing differently based on activity demands. The gastrocnemius, primarily composed of fast-twitch (type II) fibres, facilitates explosive movements such as sprinting and jumping. Conversely, the soleus provides sustained, low-intensity force for activities like walking and standing. This functional distinction underscores the need to evaluate each component individually when assessing injuries. The anatomical and functional interplay within the triceps surae complex underpins its susceptibility to various types of injuries. Understanding the intricate anatomy, including the variability of connective tissue structures and their contributions to function, is essential for accurate diagnosis, targeted treatment, and tailored rehabilitation.

CLINICAL PRESENTATION AND INJURY MECHANISM

Understanding the clinical presentation and mechanisms of injury for the triceps surae complex is critical for accurate diagnosis and effective management. While the calf complex functions as an integrated unit, the medial gastrocnemius (MG) and soleus muscles exhibit distinct injury patterns due to their anatomical and functional differences.

Medial gastrocnemius muscle

Injuries to the MG typically occur during activities that involve rapid, forceful eccentric contractions, such as pushing off during running or jumping. Common mechanisms include:

• Simultaneous knee extension and ankle dorsiflexion.
• Sudden transitions from a lengthened position to forceful contraction, such as during explosive movements.

Patients often describe a sudden sensation akin to being struck on the calf, frequently accompanied by a “snap” or “pop” sound, followed by acute, sharp pain in the posteromedial calf region. Key clinical findings include:

• Pain and tenderness localized to the muscle belly or myotendinous junction (MTJ).
• Edema and ecchymosis that may extend proximally or distally.
• Provocative tests: Significant pain during passive ankle dorsiflexion or resisted plantarflexion.

Early and precise clinical evaluation is crucial to distinguish MG injuries from other causes of posterior leg pain, such as deep vein thrombosis or Achilles tendon pathology.

Soleus muscle

Soleus injuries are more commonly seen in endurance athletes and older individuals, often resulting from repetitive overuse or high training loads¹³, The soleus muscle mostly comprises slow-twitch fibres, occasionally subjected to explosive activities. Moreover, an injury to the soleus muscle may be underestimated and perceived as clinically insignificant. The diagnosis of these injuries is often delayed due to underdiagnosis on US and given the fact that only MRI is capable of confirming the diagnosis⁴.

Unlike the MG, which is prone to acute tears, soleus injuries are frequently subacute or chronic and associated with:

• Prolonged running or training overload.
• Low-velocity activities with postural demands, such as walking or jogging.

Soleus injuries are often underdiagnosed due to their subtle and variable symptoms. Common presentations include:

• Gradual onset of calf tightness or stiffness, leading to reduced athletic performance⁵.
• Diffuse pain patterns that may extend to the lateral leg or posterior ankle.
• Delayed symptom recognition: Symptoms often subside within hours or days, causing athletes to resume activity prematurely, increasing the risk of reinjury.

In contrast to gastrocnemius strains, pain may not consistently manifest in the posterior and medial aspects of the leg; rather, it varies based on the damaged myotendinous junction and the patient may have referred pain in the lateral region of the leg.

Following the initial episode, the symptoms typically resolve within hours or days, leading the patient to perceive it as minor muscle discomfort, resulting in a lack of medical consultation and a prompt return to athletic activities. The underdiagnosis of these injuries, inadequate treatment, and premature return to sports result in a torpid progression with elevated reinjury rates.

IMAGING METHODS FOR CALF INJURIES

Accurate imaging is integral to diagnosing and managing calf injuries, offering critical insights into the type, location, and severity of damage. Ultrasound (US) and magnetic resonance imaging (MRI) are the primary modalities used, each with distinct strengths and limitations

US is often the first-line imaging modality due to its accessibility, cost-effectiveness, and dynamic capabilities³. It is particularly effective for diagnosing superficial injuries, such as those involving the medial gastrocnemius (MG) and the plantaris muscle^3,14.

Advantages:

• Real-time assessment of dynamic muscle-tendon interactions during ankle movements.
• Identification of intermuscular hematomas, fiber disruptions, and aponeurotic tears.
• High repeatability, allowing for serial evaluations during recovery.

Limitations:

• Reduced sensitivity for deeper structures like the soleus muscle.
• Operator dependency, requiring advanced expertise for accurate interpretation.

MRI is considered the gold standard for evaluating complex or deep-seated injuries, especially when US findings are inconclusive. It provides unparalleled soft-tissue contrast, making it ideal for characterizing soleus injuries and aponeurotic damage.

Advantages:

• Comprehensive visualization of both superficial and deep structures, including the central tendon and aponeuroses.
• Detailed assessment of injury extent, including interstitial edema, connective tissue disruption, and myotendinous junction involvement.
• Superior diagnostic accuracy for soleus injuries, which are often missed on US.

Limitations:

• Higher cost and reduced accessibility compared to US.
• Static imaging, which cannot assess dynamic muscle function.

Medial gastrocnemius muscle

US is the preferred modality for MG injuries, capable of identifying fiber disruptions, aponeurotic tears, and associated hematomas. Dynamic US assessments can reveal asynchronous movement between the MG and soleus muscles, indicative of significant aponeurotic damage. MRI may be used in complex cases to confirm findings or evaluate concomitant injuries.

When evaluating medial gastrocnemius injuries, there are 5 main components that should be assessed:

• MG aponeurosis
• FGA
• Fibroadipose septums and muscle fibres
• Presence of intermuscular haematoma
• Alteration of the synchronous movement between MG and soleus

Taking as a reference the US classification of MG injuries³, we’re going to describe all the injuries that can affect the MG. As shown in Figure 1, we have different components to consider in MG injuries and thus, we can define 5 different injuries classified into 4 types (Table 1).

Type 1

Injury affecting the distal myotendinous junction (MTJ) of the MG. The MG aponeurosis is intact. There is no intermuscular hematoma and the only findings that can be seen are some waviness or minor tearing/architectural distortion involving the muscle fibres that are attached to that MG aponeurosis (Figure 3)

Type 2

Type 2 injuries are probably the most complex to understand. The key point when assessing these injuries is to use ultrasound in the transverse plane, as this allows evaluation of the whole width of the MG aponeurosis. Starting from this premise, we can divide type 2 injuries into type 2A and type 2B.

All type 2 injuries involve the MG aponeurosis. The main difference between type 2A and 2B is how much of the MG aponeurosis is affected by its width.

The most important finding in type 2A is that the width affection of the MG aponeurosis is less than 50% of its total width. Fibroadipose septums and muscle fibres are affected and there may be some intermuscular haematoma (as the affection of the aponeurosis is not so big, this haematoma is not usually large) (Figure 4).

In this case, the affection of the MG aponeurosis is more than 50% of its width. Fibroadipose septums and muscle fibres are affected and there is usually a large haematoma (Figure 5).

An injury to the GA aponeurosis can affect the synchronous movement between the MG and the soleus muscle on dynamic ultrasound assessment during plantarflexion-dorsiflexion. The loss of synchronicity is related to the extent of aponeurosis involvement i.e., the greater the disconnection between MG aponeurosis and soleus posterior aponeurosis, the greater the loss of synchronous movement. Therefore, type 2B will normally show an asynchronous movement, while type 2A will normally show the correct functionality of the MG and the soleus.

Type 3

Type 3 injuries are particularly complex injuries especially when managing them. All the structures mentioned look normal and the only image that can be seen is a mild hypertrophy in the distal MTJ of the MG and a clear extension and damage of the FGA. There is no intermuscular hematoma, and the synchronous movement is generally preserved (Figure 6).

Type 4

Type 4 injury is very easy to describe. It looks the same as a type 2B injury with the addition of a rupture of the FGA, so the synchronous movement is normally affected (Figure 7).

Soleus muscle

Due to its deep location and complex anatomy, soleus injuries are best assessed with MRI, particularly when US findings are inconclusive or absent. MRI is essential for identifying aponeurotic tears, central tendon involvement, and intramuscular edema, which are key prognostic factors.

There are different locations where soleus injuries can occur, but the most important thing is how to manage these injuries. As described by scientific literature, it is very difficult to classify and assess the prognosis of soleus injuries ^5–7 and this is probably the reason why the best classification for soleus injuries is the one proposed by Prakash et al. (2017)¹⁵. It divides soleus injuries into:

• Grade 0 (oedema adjacent to connective tissue)
• Grade 1 (oedema + myofibril detachment)
• Grade 2 (aponeurosis involvement)
• Grade 3 (aponeurosis complete rupture + retraction).

As several studies have demonstrated, the more connective tissue that is affected, the worse the prognosis^2,16–20.

Although there has been an improvement in the knowledge of soleus muscle anatomy and injury distribution^10,12,21, there is still a variable understanding of the potential relationship between different types of injuries and related prognosis and RTP.

We can describe 6 different injury locations in the soleus muscle (Table 2):

• Proximal soleus tendinous arch
• Medial aponeurosis
• Lateral aponeurosis
• Central tendon
• Anterior aponeurosis
• Posterior aponeurosis

It is important to understand and consider the extremely high anatomical variability that can be found in the soleus muscle, especially regarding the medial and lateral aponeurosis and the central tendon. For example, if we have a soleus muscle with a lateralized central tendon, a small and thin lateral aponeurosis and a long and thick medial aponeurosis that crosses almost the whole soleus muscle belly, we need to consider that the worse prognosis injury in this individual soleus will be the injury of the medial aponeurosis because it is the most dominant structure in this soleus¹².

1. Proximal tendinous arch injuries

These injuries are often misdiagnosed and are common injuries, especially in veteran players and older athletes. They generally occur in the context of prior degeneration of the connective tissue and are very prone to reinjury due to several factors, such as previous degeneration of the aponeurosis, mild symptomatology from the beginning and short-lived symptoms (Figure 8).

These injuries can produce a complete rupture of the proximal tendinous arch without retraction or loss of tension as this is not a “hanging” aponeurosis like the lateral or the medial ones or the central tendon.

2. Medial aponeurosis and lateral aponeurosis injuries

Injuries affecting the medial and lateral aponeurosis are the most common ones along with the central tendon injuries. The most important aspect to assess for the prognosis is if there is a complete rupture of the aponeurosis and if the aponeurosis is a dominant one (Figures 9 and 10).

3. Central tendon injuries

Injuries affecting the central tendon are considered the ones with a worse prognosis⁵, as this is the structure that directly inserts onto the AT (Figure 11).

4. Anterior and Posterior aponeurosis injuries

Once considered as fascial structures^5,10, recent studies classified them as more structural than functional aponeurosis. Injuries affecting the posterior aponeurosis can produce a linked injury in combination with the MG aponeurosis and/or with an intermuscular haematoma that comes from the soleus posterior aponeurosis injury (Figures  12 and 13).

Another clinical situation may be a continuous muscle overload that ends up causing a myofibrillar rupture at a distance from any myoconnective junction. It is characterized by a myofibrillar tear in an area of ill-defined oedema related to the overloaded area and it is quite common in the soleus muscle (Figure 14).

Plantaris injuries

The plantaris muscle originates from the lateral supracondylar ridge of the femur, just above the knee joint, and its tendon runs distally, passing posterior to the knee joint and traveling between the gastrocnemius and soleus muscles. The plantaris tendon inserts into the calcaneus via the Achilles tendon, contributing to the formation of the calcaneal fascia.

Despite its small size, it has a variable presence in a significant portion of the population and shows very variable anatomical characteristics. The muscle may exhibit considerable variability in tendon size and length, other than differences in its trajectory and insertions^22–24. Some individuals have an absent or rudimentary plantaris muscle. This anatomical variability can have a role in Achilles tendinopathy²⁵  and it can have a similar effect on the PA of soleus and GA which may contribute to the most common site of MG injury occurring adjacent to the passage of the plantaris tendon.

Functionally, the plantaris assists in plantar flexion of the foot and flexion of the knee, though its contribution is relatively minor compared to the larger gastrocnemius and soleus muscles.

Injuries affecting the plantaris MTJ are uncommon and can be seen in US. They’re located more proximal than MG injuries where the plantaris MTJ can be found (Figure 15).

Complications and other conditions

One important complication directly related to calf injuries occurs in approximately 10% of cases. This is deep vein thrombosis (DVT), a condition that should always be considered, as it can be readily diagnosed using ultrasound (US). The classical risk factors of Virchow’s triad—venous stasis, vein wall injury, and hypercoagulability—can manifest during or after a calf muscle injury²⁶.

Suspicion of DVT arises with symptoms such as a sudden increase in pain, tenderness, warmth, and asymmetrical swelling.

US is the imaging method of choice for diagnosing DVT. It allows visualization of a thrombus causing vein occlusion (Figure 16). During the examination, the probe is gently used to compress the affected vein. The inability to compress the vein is diagnostic for DVT.

Another lesser-known condition, not yet reported in the literature, may also cause nonspecific pain and discomfort in the calf while increasing the risk of injuries. This involves an abnormal proliferation of adaptive veins, particularly in the transitional region between the deep posterior compartment and the superficial posterior compartment. These veins are distributed throughout the superficial posterior compartment of the leg, especially within the soleus muscle, where they cross aponeuroses and create weak points in these structures.

Furthermore, their incomplete functionality leads to a degree of venous stasis, which may result in sensations of heaviness, discomfort, or fatigue during physical activity. This condition is characteristic of veteran athletes and is generally associated with accumulated overload over years of activity (Figure 17).

TREATMENT CONSIDERATIONS

The successful management of calf injuries requires a comprehensive understanding of the injury’s type, severity, and anatomical structures involved. While accurate imaging is critical for diagnosis, tailored clinical management is essential for achieving optimal outcomes and minimizing the risk of reinjury²⁷. Initial treatment generally follows the RICE protocol—Rest, Ice, Compression, and Elevation—to minimize inflammation, reduce pain, and prevent further damage in the acute phase. Analgesics and non-steroidal anti-inflammatory drugs (NSAIDs) may also be employed judiciously to control pain, though their use should be balanced with the need for optimal tissue healing, as overuse of anti-inflammatory medication can interfere with the inflammatory process essential for proper tissue repair²⁸. Novel therapies such as orthobiologics hold a potential role in this process²⁹.

After the initial acute phase, the emphasis gradually shifts to restoring function and promoting a return to activity²⁸. This involves a combination of stretching and strengthening exercises tailored to the specific injured muscle—whether it be the medial gastrocnemius, soleus, or plantaris. Eccentric strengthening exercises are particularly important for calf muscle rehabilitation, as they help build resilience and minimize the risk of recurrence³⁰. In cases of injuries involving the soleus, careful attention must be given to restoring the intricate balance of postural stability, as the soleus predominantly consists of slow-twitch fibers that contribute significantly to static and low-velocity movements⁵. Controlled loading through progressive resistance training should be introduced to support tissue regeneration and regain muscle strength without overloading the recovering structures.

Patient education is another fundamental aspect of treatment. Athletes must be made aware of the risks of premature RTP, especially given the high reinjury rates associated with underdiagnosed or poorly managed calf injuries. A gradual return, guided by objective measures of muscle strength, range of motion, and functional performance, is crucial to avoid setbacks³¹. Monitoring subjective feedback on pain or tightness alongside imaging findings can also assist in tailoring the progression of rehabilitation exercises and ensuring a safe return to sporting activities. By combining imaging insights with targeted clinical management, the likelihood of a full recovery with minimal risk of reinjury can be maximized.

CONCLUSIONS

Calf injuries are common but complex musculoskeletal injuries that require a detailed understanding of anatomy, injury mechanisms, and appropriate diagnostic and management strategies. The integration of advanced imaging modalities, such as ultrasound and MRI, with clinical assessment plays a pivotal role in ensuring accurate diagnosis and guiding treatment. A tailored rehabilitation approach, informed by the specific muscle injured and its functional demands, is essential for optimal recovery and reducing the risk of reinjury.

By combining anatomical insights, evidence-based practices, and individualized care, clinicians can improve the prognosis and facilitate a safe and effective return to activity, supporting both recreational and elite athletes in achieving their performance goals.

Carles Pedret MD, PhD

Clinica Diagonal, Sports Medicine and imaging department

Esplugues de Llobregat, Spain

Stefano Palermi MD

UniCamillus Saint Camillus International

University of Health Sciences

Rome, Italy

Sandra Mechó MD, PhD

Radiology department. Clinica Creu Blanca

 Barcelona, Spain

Gulraiz Ahmad MD, PhD

Radiology department,

Manchester University NHS Foundation Trust,

Manchester, UK

Justin C. Lee FRCR

Fortius Clinic London,

London, United Kingdom

Honorary Associate Professor

Department of Surgery and Interventional Science

University College London

London, United Kingdom

Contact: info@carlespedret.com

References

1.              Orchard JW, Seward H, Orchard JJ. Results of 2 Decades of Injury Surveillance and Public Release of Data in the Australian Football League. Am J Sports Med. 2013;41(4):734-741. doi:10.1177/0363546513476270

2.             Traumatology SG of the M and TS from the SS of S, Balius R, Blasi M, et al. A Histoarchitectural Approach to Skeletal Muscle Injury: Searching for a Common Nomenclature. Orthop J Sports Med. 2020;8(3):2325967120909090-2325967120909090. doi:10.1177/2325967120909090

3.             Pedret C, Balius R, Blasi M, et al. Ultrasound classification of medial gastrocnemious injuries. Scand J Med Sci Sports. 2020;30(12):2456-2465. doi:10.1111/sms.13812

4.             Balius R, Rodas G, Pedret C, Capdevila L, Alomar X, Bong DA. Soleus muscle injury: sensitivity of ultrasound patterns. Skeletal Radiol. Published online 2014. doi:10.1007/s00256-014-1856-z

5.             Pedret C, Rodas G, Balius R, et al. Return to Play After Soleus Muscle Injuries. Orthop J Sports Med. Published online 2015. doi:10.1177/2325967115595802

6.             Green B, Pizzari T. Calf muscle strain injuries in sport: A systematic review of risk factors for injury. Br J Sports Med. 2017;51(16):1189-1194. doi:10.1136/bjsports-2016-097177

7.             Green B, Lin M, McClelland JA, et al. Return to Play and Recurrence After Calf Muscle Strain Injuries in Elite Australian Football Players. American Journal of Sports Medicine. 2020;48(13):3306-3315. doi:10.1177/0363546520959327

8.             Blitz NM, Eliot DJ. Anatomical Aspects of the Gastrocnemius Aponeurosis and Its Insertion: A Cadaveric Study. The Journal of Foot and Ankle Surgery. 2007;46(2):101-108. doi:10.1053/J.JFAS.2006.11.003

9.             Dalmau-Pastor M, Fargues-Polo B, Casanova-Martínez D, Vega J, Golanó P. Anatomy of the Triceps Surae: A Pictorial Essay. Foot Ankle Clin. 2014;19(4):603-635. doi:10.1016/J.FCL.2014.08.002

10.           Balius R, Alomar X, Rodas G, et al. The soleus muscle: MRI, anatomic and histologic findings in cadavers with clinical correlation of strain injury distribution. Skeletal Radiol. 2013;42(4):521-530. doi:10.1007/s00256-012-1513-3

11.            Koulouris G, Ting AYI, Jhamb A, Connell D, Kavanagh EC. Magnetic resonance imaging findings of injuries to the calf muscle complex. Skeletal Radiol. 2007;36(10):921-927. doi:10.1007/s00256-007-0306-6

12.            Pedret C, Rupérez F, Mechó S, Balius R, Rodas G. Anatomical Variability of the Soleus Muscle: A Key Factor for the Prognosis of  Injuries? Sports Med. 2022;52(11):2565-2568. doi:10.1007/s40279-022-01731-x

13.            Bryan Dixon J. Gastrocnemius vs. soleus strain: how to differentiate and deal with calf muscle injuries. Curr Rev Musculoskelet Med. 2009;2(2):74-77. doi:10.1007/s12178-009-9045-8

14.            Isern-Kebschull J, Pedret C, García-Diez AI, et al. Magnetic resonance classification proposal for medial gastrocnemius muscle injuries. Quant Imaging Med Surg. 2023;0(0):0-0. doi:10.21037/qims-24-298

15.            Prakash A, Entwisle T, Schneider M, Brukner P, Connell D. Connective tissue injury in calf muscle tears and return to play: MRI correlation. Br J Sports Med. 2018;52(14):929-933. doi:10.1136/bjsports-2017-098362

16.           Macdonald B, Mcaleer S, Kelly S, Chakraverty R, Johnston M, Pollock N. Hamstring rehabilitation in elite track and field athletes: applying the British Athletics Muscle Injury Classification in clinical practice. Br J Sports Med. Published online 2019:bjsports-2017-098971. doi:10.1136/bjsports-2017-098971

17.            Patel A, Chakraverty J, Pollock N, Chakraverty R, Suokas AK, James SL. British athletics muscle injury classification: A reliability study for a new grading system. Clin Radiol. 2015;70(12):1414-1420. doi:10.1016/j.crad.2015.08.009

18.            Pollock N, Patel A, Chakraverty J, Suokas A, James SLJ, Chakraverty R. Time to return to full training is delayed and recurrence rate is higher in intratendinous ('c’) acute hamstring injury in elite track and field athletes: Clinical application of the British Athletics Muscle Injury Classification. Br J Sports Med. 2016;50(5):305-310. doi:10.1136/bjsports-2015-094657

19.           Isern-Kebschull J, Pedret C, Mechó S, et al. MRI findings prior to return to play as predictors of reinjury in professional athletes: a novel decision-making tool. Insights Imaging. 2022;13(1):203. doi:10.1186/s13244-022-01341-1

20.           Valle X, Alentorn-Geli E, Tol JL, et al. Muscle Injuries in Sports: A New Evidence-Informed and Expert Consensus-Based Classification with Clinical Application. Sports Medicine. 2017;47(7):1241-1253. doi:10.1007/s40279-016-0647-1

21.            Bolsterlee B, Finni T, D’Souza A, Clarke EC, Herbert RD, Eguchi J. Three-dimensional architecture of the whole human soleus muscle in vivo . PeerJ. 2018;6:e4610. doi:10.7717/peerj.4610

22.           Spang C, Alfredson H, Docking SI, Masci L, Andersson G. The plantaris tendon. Bone Joint J. 2016;98-B(10):1312-1319. doi:10.1302/0301-620X.98B10.37939

23.           Vlaic J, Josipovic M, Bohacek I, Jelic M. The plantaris muscle: too important to be forgotten. A review of evolution, anatomy, clinical implications and biomechanical properties. J Sports Med Phys Fitness. 2019;59(5). doi:10.23736/S0022-4707.18.08816-3

24.           Gonera B, Kurtys K, Paulsen F, et al. The plantaris muscle – Anatomical curiosity or a structure with important clinical value? – A comprehensive review of the current literature. Annals of Anatomy - Anatomischer Anzeiger. 2021;235:151681. doi:10.1016/j.aanat.2021.151681

25.           Alfredson H. Persistent pain in the Achilles mid-portion? Consider the plantaris tendon as a possible culprit! Br J Sports Med. 2017;51(10):833-834. doi:10.1136/bjsports-2016-097360

26.           Stone J, Hangge P, Albadawi H, et al. Deep vein thrombosis: pathogenesis, diagnosis, and medical management. Cardiovasc Diagn Ther. 2017;7(Suppl 3):S276-S284. doi:10.21037/cdt.2017.09.01

27.           Palermi S, Massa B, Vecchiato M, et al. Indirect Structural Muscle Injuries of Lower Limb: Rehabilitation and Therapeutic Exercise. J Funct Morphol Kinesiol. 2021;6(3). doi:10.3390/jfmk6030075

28.           Järvinen TAH, Järvinen TLN, Kääriäinen M, et al. Muscle injuries: optimising recovery. Best Pract Res Clin Rheumatol. 2007;21(2):317-331. doi:10.1016/j.berh.2006.12.004

29.           Palermi S, Gnasso R, Belviso I, et al. Stem cell therapy in sports medicine: current applications, challenges and future perspectives. J Basic Clin Physiol Pharmacol. 2023;34(6):699-706. doi:10.1515/jbcpp-2023-0200

30.           Palermi S, Vittadini F, Vecchiato M, et al. Managing Lower Limb Muscle Reinjuries in Athletes: From Risk Factors to Return-to-Play Strategies. J Funct Morphol Kinesiol. 2023;8(4). doi:10.3390/jfmk8040155

31.            Draovitch P, Patel S, Marrone W, et al. The Return-to-Sport Clearance Continuum Is a Novel Approach Toward Return to Sport and Performance for the Professional Athlete. Arthrosc Sports Med Rehabil. 2022;4(1):e93-e101. doi:10.1016/j.asmr.2021.10.026

Header by David Iglesias (Cropped)