WHAT IS A CALF STRAIN?
- The muscle group that is located in the back of the lower leg and referred to as “the calf,” is made up of three different muscles: the gastrocnemius, soleus and plantaris.
- A calf strain occurs when one of these muscles is suddenly overstretched resulting in injury. These muscle strains or tears are common, and often occur with sport and rapid movements, and is commonly known as "tennis leg."
- Calf strains are categorized into three grades based on severity of muscle fiber damage, which impacts treatment and recovery outcomes [Prakash et al, 2018]:
- Grade 1: Mild strain with minimal muscle fiber damage, causing localized pain and minimal loss of strength.
- Grade 2: Moderate strain with a greater number of damaged muscle fibers, leading to more significant pain, swelling, and reduced muscle strength.
- Grade 3: Severe strain involving a complete tear of the muscle, resulting in severe pain, swelling, and a complete loss of muscle function.
HOW DO YOU KNOW IF YOU HAVE A CALF STRAIN?
- The symptoms of a calf strain, including those involving the soleus and gastrocnemius muscles, typically include [Millar, 1979; Green et al, 2020; Noonan & Garrett, 1999; Russell et al, 2000; Pai & Pai, 2007; Garrett, 1996]:
- Acute onset of pain:
Patients often report a sudden, sharp pain in the calf at the time of
injury, which is commonly associated with activities that involve rapid
acceleration or deceleration, such as running or jumping.
- Swelling and bruising: Swelling and ecchymosis (bruising) may develop within hours to days following the injury, particularly in more severe strains.
- Tenderness and muscle spasm: The affected area is usually tender to palpation, and muscle spasms may occur as a protective response to the injury.
- Difficulty with weight-bearing: Patients may experience difficulty walking or bearing weight on the affected leg, especially in more severe strains.
- Stiffness and limited range of motion: There may be stiffness and a reduced range of motion in the ankle and knee due to pain and swelling.
- Palpable defect: In cases of complete muscle tears, a palpable defect or gap in the muscle may be felt.
HOW IS A CALF STRAIN DIAGNOSED?
- Diagnosis of a calf strain is based on detailed history, physical examination, and imaging, which are crucial for a correct diagnosis and proper management. During the physical examination, a series of provocative tests may be utilized to further determine presence of injury.
- The correlation between injury grade and return to sport is well-documented with higher grades of injury are associated with longer recovery times [Prakash et al, 2018]. This puts added emphasis on the importance of accurate grading to predict recovery and guide management.
- The severity of the injury, as classified by MRI, correlates strongly with how long it takes an athlete to return-to-sport [Sergot et al, 2023].
- Ultrasound can also be a valuable tool for the diagnosis and grading of calf muscle strains [Yoshida et al, 2019; Bianchi et al, 1998; Pedret et al, 2020; Kwak et al, 2006; Balius et al, 2014].
HOW IS A CALF STRAIN TREATED?
Conservative Treatment
- Initial treatment consists of rest, NSAIDs, activity modification and physical therapy. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used for pain relief and physical therapy may be utilized once the injury has begun to heal, to improve strength and flexibility.
- Grading of calf strains can help impact treatment strategies and predict recovery by helping to tailor the rehabilitation programs and provide realistic expectations for return to sport [Prakash et al, 2018].
- Grade 1 Injury:
Grade 1 strains often respond well to conservative
management, including rest, ice, compression, and elevation (RICE),
followed by a gradual return to activity. These are characterized by a mild calf strain involving minimal muscle fiber damage. Patients
typically experience localized pain and minimal loss of strength.
Recovery time is generally short, with a mean return to play (RTP) of
approximately 17 days. - Grade 2:
Grade 2 strains may require a longer period of immobilization and a more structured rehabilitation program to restore strength and
flexibility. These are a moderate strain with a greater number of damaged muscle
fibers, leading to more significant pain, swelling, and reduced muscle
strength. The mean RTP for grade 2 injuries is around 25 days. - Grade 3:
Grade 3 strains often necessitate a more extended period of
immobilization, physical therapy, and sometimes orthobiologic injections or surgical intervention, depending on the extent of the tear and functional impairment. These are severe strains involving a complete tear of the muscle,
resulting in severe pain, swelling, and a complete loss of muscle
function. The mean RTP for grade 3 injuries is significantly longer,
averaging 48 days.
Hematoma Aspiration
- Hematomas are blood formations that can be associated with calf strains. Hematomas are areas of liquefied or coagulated blood and swelling, and can be a common complication of a calf strain [Aspelin et al, 1992; Thorsson et al, 1997].
- Hematomas can impact the clinical course of the recovery, and draining the calf hematoma can provide symptomatic relief and potentially expedite recovery in patients with calf strains [Cicvaric et al, 2006]
- The use of ultrasound guidance enhances the accuracy and safety of the procedure, and ultrasound-guided aspiration of hematomas have been shown to be a safe and effective procedure [Yoon et al, 2021].
- In a study by Trunz et al. the authors studied the effectiveness of hematoma aspiration combined with PRP injections for the treatment of hamstring strains in athletes. The study found that this combined approach significantly reduced the return-to-play time and recurrence rate compared to conservative treatment alone, suggesting that hematoma aspiration can facilitate faster recovery [Trunz et al, 2022]. This study has not been replicated for calf strains and hematoma.
Platelet Rich Plasma (PRP) Injections
- Depending on the location of the muscle strain, PRP may be a treatment option. PRP is a form of minimally invasive non-surgical, regenerative medicine that uses the patient’s own platelets to promote the healing of the injured area. The evidence for platelet-rich plasma (PRP) injections in the treatment of calf strains is mixed and somewhat limited, but based on the below studies may accelerate recovery and result in a faster return to activity for calf strains:
- In a retrospective observational study by Borrione et al., patients with gastrocnemius strains treated with PRP injections had a significantly shorter time to return to walking without pain and to full sports activity compared to those receiving standard therapy. This suggests that PRP may accelerate functional recovery in calf strains [Borrione et al, 2018].
- In contrast, a study by Fusagawa et al. using a rat model for a calf strain found that in rats neither leukocyte-poor PRP (LP-PRP) nor leukocyte-rich PRP (LR-PRP) accelerated healing [Fusagawa et al, 2024].
- A systematic review and meta-analysis by Sheth et al. examined the efficacy of PRP in acute muscle injuries, including calf strains. The review found that PRP injections resulted in a significantly earlier return to sport compared to control therapies, but no significant difference in reinjury rates was observed. This indicates potential short-term benefits of PRP, though long-term efficacy remains uncertain [Sheth et al, 2018].
Surgical Intervention
- The surgical literature on the management of calf muscle strains, including soleus and gastrocnemius muscle tears, is limited. The majority of the literature focuses on conservative management, with surgical intervention being less common and typically reserved for more severe or chronic cases.
- There is a single case report by Cicvarić et al. that reports on the endoscopic evacuation of a hematoma resulting from a strain injury of the medial head of the gastrocnemius muscle, indicating that surgical intervention can be effective in specific cases but is not widely documented [Cicvaric et al, 2006].
