Motivated by the need for a wearable joint-angle senor capable for one-time calibration with multiple manual installations, this paper proposes a wrinkled sensor design to capture joint bending with capacitive sensing with adaptation to electrode elongation. The wrinkled capacitor structure is fabricated by releasing a pre-stretched elastic substrate adhered with a flexible conductive film. Another polyvinyl chloride (PVC) film serves as the backbone to prevent axial elongation during sensor bending. The sensor adapts to the variation of manual installation position via the constant force mechanism. The angle sensing errors were 2.886°, 2.780°, and 2.801° for the ankle, knee, and hip joints, respectively, and the tracking error for the gait phase was 1.54%. It is anticipated that the proposed method would facilitate wearable sensing for human motions with the convenience of one-time calibration.