The lumbricals are four small muscles located between the metacarpal bones of the hand. While only very small, the actions performed by the lumbricals are important for many functions of the hand, such as gripping movements. Lumbrical muscle injuries occur when a finger (middle/ring finger) is forcefully straightened while the other fingers are actively gripping/bent. Rock climbers are at greatest risk for lumbrical muscle tears.
Diagnosis
Lumbrical muscle tears can be diagnosed by stress testing (see Figure 1) and by an ultrasound scan investigation to determine the lesion grade.
- A Grade I muscle tear is a microtear and is not visible on ultrasound.
- A Grade II or III muscle tear involves injury to more muscle fibres, and both grades of tear are visible on ultrasound.
Positive stress test. Pain when the patient tries to make a fist, while examiner pulls ring finger into extension.
No pain with extension of ring and middle fingers together.
Ref: DOI: 10.1177/1753193418765716
Treatment
A study from Germany, in the European Journal of Hand Surgery (2018) recommends the following approach to treating lumbrical muscle tears: https://doi.org/10.1177%2F1753193418765716
In the case of a grade I tear, gentle pain-free stretching of the lumbricals is performed for 4-6 weeks followed by graduated loading.
For grade II muscle tears, buddy taping is recommended for a maximum of 8 weeks, followed by a similar treatment as per a grade I tear.
For a grade III muscle tear, immobilisation of the middle, ring and little finger to the proximal phalanx is recommended for 2 weeks. This is followed by the same treatment as per a grade II tear.
Healing timeframes
All injuries in this study were healed at 12 weeks. The healing period in Grade III muscle tears was significantly longer (10 weeks) than in the patients with Grade I tears (5 weeks) or Grade II tears (6 weeks).
If you are experiencing pain in your hand following a climbing injury, our team of hand therapists would be happy to assist in diagnosis and treatment. Please contact us on 355 9775.
