Brand et al. dissected 15 cadaveric forearms to measure the mass and mean fiber length of every forearm and hand muscle. These values were combined to calculate a tension fraction — each muscle's share of total physiologic cross-sectional area — and a practical excursion estimate. The resulting tables provide the quantitative foundation for tendon transfer selection.
Tendon transfer surgery had long relied on empirical observation and surgeon experience to match donors to recipients. Brand's cadaveric data gave that intuition a quantitative foundation — a surgeon could read a table and know whether a proposed donor had the right force capacity and fiber length for the job.
When selecting a donor for wrist extension reconstruction in radial nerve palsy, remember that ECRB outperforms ECRL in tension fraction (4.2% vs 3.5%) despite ECRL's larger overall size. If the transfer demands large excursion, ECRL's longer fibers are the advantage.
Before using FCU as a donor, confirm the recipient function does not demand large amplitude. Its 6.7% tension fraction is unmatched at the wrist, but its 4.2 cm fiber length caps excursion. Transferring it to a high-amplitude position wastes its strength.
When index or little finger FDS is your chosen donor, both tendons must be transferred together. The digastric anatomy means the untransferred tendon becomes a mechanical tether, not a free bystander.
Brand et al. dissected 15 cadaveric forearms to measure the mass and mean fiber length of every forearm and hand muscle. These values were combined to calculate a tension fraction — each muscle's share of total physiologic cross-sectional area — and a practical excursion estimate. The resulting tables provide the quantitative foundation for tendon transfer selection.
Tendon transfer surgery had long relied on empirical observation and surgeon experience to match donors to recipients. Brand's cadaveric data gave that intuition a quantitative foundation — a surgeon could read a table and know whether a proposed donor had the right force capacity and fiber length for the job.
When selecting a donor for wrist extension reconstruction in radial nerve palsy, remember that ECRB outperforms ECRL in tension fraction (4.2% vs 3.5%) despite ECRL's larger overall size. If the transfer demands large excursion, ECRL's longer fibers are the advantage.
Before using FCU as a donor, confirm the recipient function does not demand large amplitude. Its 6.7% tension fraction is unmatched at the wrist, but its 4.2 cm fiber length caps excursion. Transferring it to a high-amplitude position wastes its strength.
When index or little finger FDS is your chosen donor, both tendons must be transferred together. The digastric anatomy means the untransferred tendon becomes a mechanical tether, not a free bystander.