Walking canes are items that only elder Sims can use, featured in The Sims 3: Generations. . Once you have bought the cane, it can be placed into any Sim's inventory. There are three styles available for purchase, which are found in misc catalog under entertainment section (sorted by function).
When placed into an elder Sim's inventory, two options will appear. One is to give it as a gift and the other is to start using the cane. Once the latter is chosen, the elder will walk with the cane. Now there is an additional option available when clicking the cane. You can choose their walk style as the Southern Gentleman or the Geriatric Gait.
The Southern Gentleman style is a jolly gait. The Sim will strut around with no apparent difficulties. The Geriatric Gait, on the other hand, has a more "elderly" appearance. The elderly Sim will limp around with what openly looks as a walking disability. However, when the Sim doesn't use the cane they will lose the limp.