Effects of high heels on medial tibiofemoral cartilage mechanics: an exploration using musculoskeletal simulation and a probabilistic cartilage failure model

This study examined the effects of different high-heeled footwear heights on lower extremity medial tibiofemoral cartilage mechanics and longitudinal failure probability, using musculoskeletal simulation and probabilistic failure modelling approaches. The current investigation examined 24 participants, walking in four different footwear (high heel, medium heel, low heel, and trainer). Walking kinematics were collected using an 8-camera motion capture system and kinetics via an embedded force plate. Medial tibiofemoral loading was explored using musculoskeletal simulation and cartilage probability via probabilistic modelling. Distance travelled per day was inputted into the model as 6.0 km per day. This was modelled as participants completing all 6.0 km in the trainer condition whereas in the heeled footwear, this was modelled as participants completing 3.0, 2.4, 1.8, 1.2 and 0.6 km in the heels, and the remaining distance undertaken in the trainers. Cartilage forces and strains were significantly greater in the high (force = 3.39BW & strain = 0.26), medium (force = 2.98BW & strain = 0.22) and low heels (force = 2.91BW & strain = 0.22) compared to the trainer (force = 2.52BW & strain = 0.19). Cartilage failure probability was significantly greater in the high (3.0 km = 21.26%, 2.4 km = 18.45%, 1.8 km = 18.15%, 1.2 km = 17.90% & 0.6 km = 17.52%), medium (3.0 km = 9.97%, 2.4 km = 9.86%, 1.8 km = 9.76%, 1.2 km = 9.66% & 0.6 km = 9.55%) and low heels (3.0 km = 9.13%) compared to the trainer (1.89%), and in the high heel condition decreased linearly alongside reductions in modelled walking distance. The findings from the current investigation show that high heels of increasing height have a profoundly negative influence on medial knee cartilage health and strongly advocate that walking distance in heeled footwear and the heel height itself be reduced wherever possible.