Beyond heel raises: Top calf injury assessment tips for physios

Calf injury assessment has evolved considerably in the last few decades. While we used to simply use a max-repetition heel raise test, we now understand the high magnitudes and rates of loading the calf experiences; ankle and foot mobility may also be affected by calf injury and can be a risk factor for future injuries. Additionally, we’ve learned that after injury, calf muscle function may not return to “normal”, with the soleus often exhibiting deficits, so we need to assess the performance of each calf muscle individually.

The components of our exam will include:

• Subjective interview
• Functional assessments
• Strength and impulse loading assessment
• Additional tests (mobility, palpation, synergist muscle assessment, and neurological testing)

In this blog, we’ll walk through expert physiotherapist Craig Purdam’s Practical on calf injury assessment.

If you’d like to see exactly how expert physio Craig Purdam assesses calf injuries, watch his full Practical HERE. With Practicals, you can be a fly on the wall and see exactly how top experts assess and treat specific conditions – so you can become a better clinician, faster. Learn more here.

Subjective exam

The subjective exam sets the stage to guide our objective assessment, and to establish a roadmap for recovery. We need to gather information, including:

• History of previous calf injuries
• History of other lower extremity injuries, especially those of the ankle, knee, toe or foot
• Whether the injury was traumatic or insidious onset
• Patient goals and sporting/load demands

Of course, we need to include red flag screening questions, to catch conditions such as lumbar spine pathology or peripheral arterial disease.

Functional assessments

We can use functional assessments to examine movement quality. This can include activities such as heel raises, walking, and hopping. These assessments are sequenced to gradually increase the load demands on the calf. Recording a video of these movements can be a great source of feedback and sets a benchmark for reassessment down the road.

Heel raises

The heel raise is an excellent way to observe muscle quality and performance. Start with an isometric heel raise to compare left and right muscle size and tone. Next, we’ll have the patient perform single leg heel raises in knee-extended and knee-flexed positions (the latter biases the soleus). During the heel raise, we are looking for major movement deviations (e.g. poor eccentric control) and perceived exertion for each side.

Walking

When assessing gait, we are looking for major asymmetries between the left and right, such as excessive trunk lean and differences in stride length. After walking, we’ll observe light jogging, where we’re on the lookout for issues such as poor push-off.

Hopping

To increase the loading demands of the calf, we’ll look at submaximal hopping. It’s best to start with submaximal hopping because it better isolates calf function, whereas maximal hopping involves more of the kinetic chain. When observing hopping, look for deficits such as poor eccentric control, compare left and right sides, and check for pain and perceived exertion.

We can use the following hopping sequence, which gradually increases demands on the calf musculature:

• Vertical single-leg hops (i.e. hops in place)
• Single-leg hops onto a 15 centimeter step
• Horizontal single-leg hops (i.e. hops moving forward)

Craig describes how the horizontal hopping test provides us with insights on a patient’s readiness for return to running. See the below snippet from his Practical:

Strength and impulse loading assessments

Strength assessment

To assess strength, start with a 5 repetition-maximum unilateral heel raise, with the knees flexed using roughly 50% bodyweight loads. Then we’ll repeat the assessment but remove the contribution of the long toe flexors by having the toes unsupported, hanging off the edge of a step. To analyse gastrocnemius performance, we’ll examine single-leg heel raises performed on a Smith machine with the body angled at 45-degrees and with the knees extended. We can see how Craig uses this novel exercise to challenge the gastrocnemius muscle in this video from his Practical:

We also want to examine maximal strength using a 1 repetition-maximum test, ideally using a load cell, which provides superior accuracy. If you have access to such equipment, this test would be performed in knee-flexed and knee-extended positions.

Impulse loading assessment

With strength assessment we are examining the calf’s capacity for force production, whereas, with our impulse loading assessment we examine its capacity to produce force rapidly and repetitively. We’ll start by performing rapid single-leg heel raises, using hand support for balance and a metronome for pacing. The patient will perform 20-30 “pulses” with the knees flexed, at a rate of 132 beats per minute, as Craig shows us in this excerpt from his Practical:

Next, similar to the strength assessment, we’ll repeat those pulses but remove the contribution of the long toe flexors, by having the toes unsupported, hanging off the edge of a step.

For higher level athletes, the metronome pacing may be increased depending on their sporting demands. We can also increase the intensity of the test by instructing the patient to perform heel raises more forcefully.

Additional tests

Mobility

We’ll examine ankle and foot Range Of Motion (ROM), starting with checking knee-to-wall distance, which examines closed-kinetic-chain dorsiflexion mobility. If there are restrictions in dorsiflexion, further examination of common areas of restriction like the talo-crural joint and the inferior tibio-fibular joint may be appropriate. Another common deficit is limited first metatarsal-phalangeal (MTP) extension ROM, which is crucial for proper push-off. First MTP extension and dorsiflexion ROM are some of the most common restrictions, you may need to assess other areas of ankle and foot mobility depending on your patient’s presentation.

Palpation

When palpating, we are primarily assessing the tenderness and tone of the muscles. The primary muscles to palpate include the gastrocnemius, soleus, Flexor Hallucis Longus (FHL), and plantaris.

Synergist muscle assessment

With calf injury assessment, we may need to examine two commonly affected muscles: the plantaris and FHL. To assess for plantaris injury, have the patient perform heel raises starting from a maximally dorsiflexed position with the knees extended. If the patient experiences pain in the area between the midpoint of the gastrocnemius to the medial gastrocnemius insertion, they may have suffered a plantaris injury. For the FHL, we’ll assess its function using manual muscle testing.

Neurological testing

Based on the subjective exam, some neurological testing may be necessary. This testing would start with clearing the lumbar spine by performing quadrant testing, and assessing lumbar range of motion. Next we can perform the slump test, as well as quadriceps and ankle jerk reflexes.

Wrapping up

With recent advances in calf injury research, physios are encouraged to complete a comprehensive assessment, including testing with high magnitudes and rates of loading, examination of ankle and foot mobility, and assessing isolated muscle function. The assessment should be tailored to the patient’s goals and sporting demands, with thorough subjective and objective assessments. Completing this thorough assessment gives you the best chance to set you and your patient up for a successful course of treatment.

If you want to know more about how expert physio Craig Purdam assesses calf injuries, watch his full Practical HERE.