Wearing high heels alters walking kinematics and kinetics and can create potentially adverse effects on the body. Our purpose was to determine how heel height affects frontal plane joint moments at the hip, knee, and ankle, with a specific focus on the external knee moment due to its importance in medial loading and knee osteoarthritis. In addition, this study examined the effect of heel height on impact acceleration of tibia and head and shock attenuation of the body. Fifteen women completed overground walking trials in three different heel height conditions (1, 5, and 9 cm) for a fixed walking speed (1.3 m/s) and a preferred walking speed while kinematic and force platform data were collected concurrently. Accelerometers were attached to the tibia and forehead in order to measure peak tibial and head acceleration and shock attenuation of the body. For both fixed and preferred speeds, peak external knee adduction moment increased systematically with an increase in heel height. Peak internal ankle eversion moment increased systematically with an increase in heel height, and though little change was evident at the hip, peak hip abduction moment was slightly higher for the 9 cm heel height compared to the 1 and 5 cm conditions. For both fixed and preferred speeds, peak tibial acceleration (PTA) was significantly higher for the 5 cm heel height condition compared to the 1 and 9 cm conditions, which was similar in PTA amplitude. Peak head acceleration (PHA) followed a similar but more subtle trend as PTA for both speed conditions. Substantial shock attenuation (70 to 75%) was responsible for the muted PHA responses in both speed conditions. Although not specifically identified, the unexpected PTA response is likely due to a combination of kinematic gait alterations that result in a lower PTA for the 9 cm heel height. This may have important implications on how heel height affects repetitive impulsive loading during walking. The higher peak external knee adduction moment with increasing heel height suggests greater medial loading at the knee, which can contribute to joint degeneration and the development of knee osteoarthritis. The kinetic changes observed at the ankle with increasing heel height may contribute to larger medial loads at the knee. Overall, wearing high heels, particularly those with higher heel heights, may put individuals at greater risk for joint degeneration and developing knee OA.