Calf strains in athletes: a narrative review of management, injury grading, and return to sport

Key points

1. 01MRI and ultrasound both offer prognostic value for calf strains, with higher-grade injuries on imaging consistently linked to longer recovery times
2. 02Aponeurotic disruption on MRI significantly extends return-to-play time compared to injuries without disruption
3. 03Soleus strains, especially those involving the central tendon, tend to have longer recovery times than gastrocnemius strains
4. 04Re-injuries take substantially longer to recover from than initial injuries, with athletes needing an extra 16.6 days to reach 90% running speed
5. 05Clinical assessment, not imaging alone, is the gold standard for return-to-sport decisions; imaging should supplement, not replace, functional evaluation

How it was conducted

Design

Narrative review following SANRA guidelines, with systematic search elements from PRISMA 2020

Databases searched

PubMed and Scopus, from inception to October 10, 2025

Studies included

11 studies (7 retrospective, plus cross-sectional, case-control, and descriptive epidemiologic studies)

Population

Athletes at various competition levels (professional to recreational) with calf muscle strains; most studies involved predominantly or exclusively male athletes

Imaging modalities

7 studies MRI only, 3 ultrasound only, 1 both MRI and ultrasound

Primary focus

Role of imaging and injury grading in predicting return to sport after calf strain

What they found

• Return-to-play times ranged widely from 2 to 102 days, with an average of 39 +/- 18 days across injury types
• Olympic Park Classification Grade 0 injuries: mean RTP 8.1 +/- 7.45 days; Grade 1: 17.2 +/- 8.84 days; Grade 2: 24.7 +/- 9.71 days; Grade 3: 48 +/- 15.95 days
• Aponeurotic disruption increased average RTP by 8.4 days (p = 0.007); injuries without disruption averaged 19.4 days, mild disruption 26.7 days, severe disruption 31.3 days
• Myofascial interface injuries averaged 20.1 days to full training versus tendon/aponeurosis injuries averaging 46.8 days (p = 0.02) in English Premiership rugby players
• Re-injuries required an extra 16.6 days to achieve running at >90% maximum speed and an extra 18.9 days to RTP compared to index injuries
• Running-related injuries took longer to recover (33.4 +/- 21.6 days) than non-running injuries (21.3 +/- 15.1 days)
• Central myotendinous junction soleus injuries resulted in approximately 25 days longer RTP than lateral myotendinous junction injuries (p = 0.044)
• Intramuscular tendon tears were strongly associated with missed games (p = 0.010); multiple muscle involvement led to 88% missing at least one game versus 47% for single-muscle injury (p = 0.017)
• Both Munich and BAMIC classification systems correlated with RTP in soleus strains (p < 0.0001); BAMIC offered better prognostic value as it includes edema evaluation
• Pedret et al. classification system showed significant relationship between injury grade and RTP/return to work (p < 0.001), with Types 3 and 4 having the worst prognosis
• AFP fascial defect size and fluid collection were associated with RTP over 2 weeks (p = 0.032 and p = 0.031 respectively) in NFL players

Limitations

• Majority of included studies were retrospective, introducing selection bias and limiting causal inference
• Most studies included fewer than 50 injuries and focused on elite or professional male athletes from a single sport, reducing generalizability to recreational athletes and women
• Rehabilitation protocols were not standardized across studies, creating unmeasured variables that could independently influence RTP timelines
• Definitions of RTP varied widely across studies, from pain-free walking to full competition participation, making direct comparisons and evidence synthesis difficult

Why it matters

For patients

Athletes who sustain a calf strain can expect recovery times broadly ranging from about 2 weeks for mild injuries to 12 weeks for severe ones, with soleus injuries and re-injuries typically taking longest.

For clinicians

Imaging grade, particularly aponeurotic disruption and tendon involvement on MRI, should inform prognosis and rehabilitation planning, but functional clinical criteria remain the primary determinant for safe return to sport.

For readers

This review synthesizes the best available evidence on imaging-guided prognosis for calf strains, highlighting that no single grading system is validated across populations and that standardization of both imaging protocols and RTP definitions is urgently needed.