When using lower limb exoskeletons, the human body naturally adopts neuromotor learning to adapt to the newly introduced conditions and interactions. However, due to the limited comprehension of human adaptation processes and strategies, defining the methodologies and metrics for identifying when and how the adaptation occurred remains a challenge. This study aims to investigate the human adaptation behaviour during exoskeleton use from the biomechanics perspective. Rather than focusing only on the statistical inferences of the general population, discrete analyses of individual participants are carried out to capture different adaptation strategies. The preliminary results indicated potential human-exoskeleton adaptation features exhibited by the converged increase of plantar flexion angle upon exoskeleton use. On the contrary, the three participants displayed unique response patterns in metabolic cost, suggesting that generally defining adaptation with only metabolic cost information may potentially be erroneous.