From the Research
Tibialis anterior weakness sparing tibialis posterior is most commonly caused by a common peroneal nerve injury or compression at the fibular head, which affects the deep peroneal nerve supplying the tibialis anterior while sparing the tibialis posterior, as supported by the study published in 2023 1.
Causes of Tibialis Anterior Weakness
The causes of tibialis anterior weakness with sparing of the tibialis posterior muscle can be attributed to several conditions, including:
- Common peroneal nerve injury or compression at the fibular head, affecting the deep peroneal nerve supplying the tibialis anterior
- L4 radiculopathy affecting primarily the anterior compartment
- Anterior compartment syndrome where increased pressure damages the tibialis anterior muscle
- Direct trauma to the tibialis anterior muscle
- Certain myopathies that preferentially affect the anterior compartment muscles
- Diabetic neuropathy with asymmetric involvement affecting the peroneal nerve more than the tibial nerve
- Multiple sclerosis and other demyelinating disorders causing isolated weakness patterns due to selective central nervous system lesions
Diagnosis and Treatment
Diagnosis typically involves physical examination, nerve conduction studies, electromyography, and sometimes imaging studies like MRI to identify the underlying cause. Treatment depends on the specific etiology but may include addressing nerve compression, physical therapy, ankle-foot orthoses for foot drop, and in some cases, surgical intervention, as discussed in the study published in 2024 2. Some key points to consider in the diagnosis and treatment of tibialis anterior weakness include:
- The importance of manual muscle testing in assessing tibialis anterior muscle weakness, as highlighted in the study published in 2023 1
- The use of electrophysiological assessments, such as compound muscle action potentials, in evaluating the function of the lumbar and sacral peripheral motor nerves, as discussed in the study published in 2024 2
- The potential benefits of surgical intervention, such as tendon transfer, in treating tibialis anterior weakness, as reported in the case study published in 2022 3