Table 1 Key domains and subcomponents of the initial subjective and objective examination of calf muscle strain injuries
Domain and sub-components | Primary clinical questions and considerations | Key concepts and/or outcomes guiding clinical decision-making |
|---|---|---|
Subjective | Â | Â |
The presenting injury | Â | Â |
 History of onset | Do you remember how or when it happened? | Symptoms from soleus injuries are at times cumulative or may not be reported until subacute examination, whereas gastrocnemius injuries are almost always apparent immediately. Gastrocnemius injuries were most common during acceleration, jumping, and sprinting activities whereas soleus injuries were most common during steady-state running or were gradual onset presentations |
 Self-reported symptoms | What are your symptoms? | Frank pain may be more common in CMSI involving gastrocnemius or severe soleus injuries |
| Â | Where are your symptoms coming from? | Location is often obvious for superficial CMSI. Poor localisation is common for deep soleus injuries |
| Â | How badly are you impacted? | Self-perceived impairment assists early estimation of prognosis, and triaging actions |
The injured athlete | Â | Â |
 Intrinsic factors | Have you injured your calf before? | Details of previous CMSI aided diagnosis and impacted prognosis (e.g. more time may be afforded athletes with a significant history) |
| Â | Do you have a history of any other lower limb injuries? | Other previous injuries may impact susceptibility to subsequent CMSI pending the impact they have had on exposure or the presence of persistent impairments that affect calf loads |
 Potential predisposing factors | Do you currently have pain or symptoms anywhere else? | Sub-clinical states elsewhere direct objective examination of contributing factors, especially when relevant to the mechanism of injury |
| Â | Have you recently been offloaded from running for any reason or has your exposure to match play or training changed recently? | Recent interruptions and/or suddenly increased running workloads were a common culprit in CMSI, particularly soleus injuries |
| Â | Have there been any other recent changes to your off-field program? | Unaccustomed heavy strength or explosive loading may reduce resilience to CMSI involving either soleus or gastrocnemius |
The injury context | Â | Â |
 Extrinsic factors | What is your sport and how would you describe your playing position/ style? | The activities performed and mechanical conditions encountered provide direction for diagnosis and prognosis |
| Â | What is the stage of the season? | Pre-season and early competition periods were associated with over-load related CMSI (e.g. re-exposure to running workloads and intensity) |
 Other contextual factors | Has anything changed about the environment you complete training and/or matches, the surface, your footwear? | Changes in surface and footwear were found to impact the work conditions of the calf. Altered work conditions as a result of these seemingly small adjustments can have a large impact on injury risk due to the high work demands on the calf in dynamic activities and large workloads of elite athletes |
Objective | Â | Â |
Observation | Â | Â |
 The calf | Is a defect observable or signs of a different pathology? | Defects and/or de-tensioning are evident in some severe CMSI, often involving gastrocnemius |
Is there a difference in relative bulk? | Structural differences can correlate with impaired calf function and may predispose to CMSI | |
 Other body regions | Does the injured side show signs of an unloading pattern elsewhere (e.g. atrophy)? | Visible difference in synergists might indicate increased calf work demands due to habitual under-loading. This may highlight other body regions to examine for predisposing factors |
Palpation | Â | Â |
 Tenderness | Which muscle is tender? | Palpation can usually differentiate muscle involvement and is most obvious for severe CMSI |
What is the maximum length of tenderness? | Palpation tenderness over a more extensive length can indicate greater severity, especially for gastrocnemius injuries | |
 Tactile qualities | Can a defect or focal spasm be located? If so, where? | Palpable tissue changes can help to confirm the location. Focal spasm often became apparent in subacute presentations of soleus injuries |
Stretch tolerance | Â | Â |
 Non weight bearing | Is passive dorsiflexion affected? | Greater range of motion deficits are evident in severe CMSI. Mild CMSI may not show reduced stretch tolerance in Non weight bearing conditions |
| Â | Does altering the knee position highlight the symptom source? | Soleus and gastrocnemius injuries may be more sensitive when stretched while the knee is flexed and extended, respectively |
 Weight bearing | How do the available range and symptom severity compare between knee extension vs knee flexion positions? | Knee position can differentiate muscle involvement to some extent (e.g. soleus vs gastrocnemius), but severe CMSI have similar weight bearing restrictions regardless of position |
Isolated function | Â | Â |
 Non weight bearing | Does isometric calf loading elicit symptoms? | Gross weakness and pain during low-load tests indicates greater severity |
| Â | Do symptoms change according to knee position? | Greater weakness and symptoms associated with knee position may differentiate muscle involvement |
 Weight bearing | What is their calf raise strength (e.g. unable vs double leg vs single leg)? Is strength impacted by altering position (knee, ankle, foot)? | The degree of strength loss is associated with severity and may be position-dependent according to the muscle (knee flexed: soleus; knee extended: gastrocnemius) |
| Â | Are there any other findings if the loading rate is increased? | Increasing the loading rate could identify subtle differences and bridge the gap between strength and plyometric testing |
Dynamic capacity | Â | Â |
 Plyometric function | What is the relative capacity for plyometric function (e.g. unable vs double leg vs single leg)? | Systematically testing graded plyometric tasks can elucidate the injury severity. Severe CMSI will not be able to perform this part of the examination |
| Â | Do the results change whether it is predominantly upwards or forwards? | Plyometrics involving forward propulsion are the most demanding; CMSI undetectable until this point are likely to be of mild severity |
 Locomotive activities | What is their capacity to walk? Jog? Stride? Sprint? Accelerate? | Relative capacity and the threshold for symptom-onset helps to identify severity. Some mild CMSI can walk and perform some running activities pain free even at the time of injury onset |