ECG Lead Placement for Below-Knee Amputees

Standard 12-lead ECG uses limb leads (RA, LA, LL, RL). For unilateral below-knee amputation (BKA):

Modified Placement

• RL (right leg / ground) – place on right anterior superior iliac spine (ASIS) or right lower abdomen.
• LL (left leg) – if residual limb ≥10 cm, place on distal stump; otherwise, left ASIS/left lower abdomen.
• RA, LA – standard wrists/deltoids.

Effect on Leads

• Lead I (LA–RA) – unchanged.
• Lead II (LL–RA) and III (LL–LA) – vectors altered; interpret with caution.
• Augmented leads (aVR, aVL, aVF) – derived from I, II, III; similarly affected.
• Precordials (V1–V6) – unaffected.

Documentation

Note "modified limb leads – left BKA" on ECG. Compare with prior tracings. If bilateral BKA, place both leg electrodes on ASIS/abdomen.