Literature

Otzi, the Iceman, was discovered in the Tyrolean Alps in 1991. He is thought to have died over 5000 years ago - and he was wearing shoes. Older remains of footwear come mainly from North America, dated to between 6500 and 9000 years ago. Earlier than that, there is a moccasin footprint in France from the Upper Palaeolithic and some cave drawings of men with footwear. Burial sites reveal beads, apparently sewn onto clothing, around the feet of the deceased. These are dated at around 24,000 years ago.

A shoe worn by Otzi, the Iceman

However, many caves identified as Palaeolithic sites have footprints revealing unshod feet. This has led to a widespread view that these people went around barefoot, despite the knowledge that they generally lived in a cold climate.
Foot bones, however, are affected by the footwear we wear, and an interesting avenue of research has been developed by Erik Trinkaus over recent years. He has noted morphological changes in the pedal phalanges of human feet resulting from the presence or absence of footwear. In 2005, he reported that:

"A comparative biomechanical analysis of the proximal pedal phalanges of western Eurasian Middle Paleolithic and middle Upper Paleolithic humans, in the context of those of variably shod recent humans, indicates that supportive footwear was rare in the Middle Paleolithic, but that it became frequent by the middle Upper Paleolithic."

Phalanges of a human foot reveal whether the individual wore shoes habitually

More recent work has compared bones of ancient humans in China with three groups of humans: recent urban Americans, late-prehistoric native Americans and late-prehistoric Inuits . Urban Americans wear shoes habitually, the native Americans went barefoot and the Inuits were hybrids regarding foot-coverings. The Palaeolithic data concerns the Middle Upper Paleolithic modern humans from Sunghir 1 (dated about 27,500 years ago) and even earlier modern humans from Tianyuan 1 (dated about 40,000 years ago). The results are summarized as follows:

"Whether the polar moments of area of the middle phalanges are compared to phalangeal length alone or to phalanx length times body mass, the habitually shod Euroamerican sample has the most gracile phalanges, the habitually barefoot Amerindian sample has the most robust phalanges, and the habitually shod but robust Inuit sample has an intermediate distribution. They are highly significantly different [. . .] for each comparison. The Middle Upper Paleolithic sample clusters largely with the Inuit sample [. . .] These data therefore reinforce the association of footwear with pedal phalangeal gracility in the Middle Upper Paleolithic. To these considerations we can now add the Tianyuan 1 partial skeleton from eastern Asia, which preserves a complete middle pedal phalanx, most likely from ray 2. Its relative pedal phalangeal robusticity, when compared to phalanx length alone, is among the more gracile of the Middle Upper Paleolithic and Puebloan phalanges, moderately gracile for an Inuit, similar to the recent Euroamericans, and completely separate from the late archaic and early modern Middle Paleolithic humans."

In conclusion: "the Tianyuan 1 pedal phalanges should be sufficient to indicate that the pattern of middle toe gracility and its probable association with habitual footwear use predates the emergence of the Middle Upper Paleolithic."

The significance of this research is that the Palaeolithic human communities have suffered from a rather stereotyped image. 'Stone age' people they were, but this does not mean that they lacked human capabilities. As research progresses, more and more features have been identified which close the gap between them and us. The problem is that we have inherited an evolutionary perspective on human origins which leads us to believe that Palaeolithic peoples were transitional between ape-men and modern man. New finds, like evidences of habitual footwear in a human thought to have lived 40,000 years ago, are continually challenging this evolutionary scenario. One day, perhaps, it will be clear that these people were just like us, but living in a harsh and dangerous environment. Then, we'll admire them for what they did achieve.

Anatomical evidence for the antiquity of human footwear: Tianyuan and Sunghir
Erik Trinkaus and Hong Shang
Journal of Archaeological Science, Article in Press

Abstract: Trinkaus [. . .] provided a comparative biomechanical analysis of the proximal pedal phalanges of western Eurasian Middle Paleolithic and Middle Upper Paleolithic humans, in the context of those of variably shod recent humans. The anatomical evidence indicated that supportive footwear was rare in the Middle Paleolithic but became frequent by the Middle Upper Paleolithic. Based on that analysis, additional data are provided for the Middle Upper Paleolithic (~27,500 cal BP) Sunghir 1 and the earlier (~40,000 cal BP) Tianyuan 1 modern humans. Both specimens exhibit relatively gracile middle proximal phalanges in the context of otherwise robust lower limbs. The former specimen reinforces the association of footwear with pedal phalangeal gracility in the Middle Upper Paleolithic. Tianyuan 1 indicates a greater antiquity for the habitual use of footwear than previously inferred, predating the emergence of the Middle Upper Paleolithic.

See also:

Trinkaus, E. Anatomical evidence for the antiquity of human footwear use, Journal of Archaeological Science, 32(10), October 2005, 1515-1526.