Junior Specialist UC Irvine Department of Neurosurgery Santa Clarita, California, United States
Introduction: Severe loss of muscle strength is common following stroke, and rehabilitation in the form of targeted physical therapy is often needed to recover partial muscular function. Although lower limb weakness is typical in stroke patients, upper body complications presenting as decreased grip strength and hand motor coordination can also occur. The biceps brachii, one of the most frequently used upper body muscles, often shows weakness post-stroke. Although recent literature has touched on various techniques to help regain biceps brachii function, studies looking at quantifiable recovery of muscular strength are limited.
Methods: In this review, we summarize strength recordings of the biceps brachii from stroke patients collected over the past 20 years to better characterize upper extremity functional recovery after stroke.
Results: 15 studies describing 384 patients (mean age range: 55.7-73.6 years) were included for formal analysis. Baseline biceps strength range following stroke was 12.1-91.23 N. At 4 weeks, strength ranged from 16.3-85.8N, and this range improved to 85.31-97.38N and 29-125.04N at 5 and 8 weeks, respectively. Additionally, Folkerts et al. found a significant improvement in biceps function from the 5 week value (97.38N) to the 10 week final follow-up (108.46N). Over 12 weeks post-stroke, Donaldson and colleagues observed a significant improvement in bicep strength range (27.1-61.0N vs. 59.5-76.1N).
Conclusion : Our study is the first systematic review assessing the recovery of biceps function with time following stroke in the current literature. Singular timepoint studies showed a significant loss of bicep function post-stroke. Multiple timepoint studies showed semi-linear relationships between biceps strength recovery and time within studies but no patterns when comparing between studies. Further research is required to quantify biceps strength recovery in a sex-specific manner.
