File:Knee brooch (profile) (FindID 836831).jpg

English: Incomplete cast copper alloy Roman knee brooch, missing its pin, most of the spring mechanism and the hook of the catchplate. The cylindrical head has a very short crossbar and the remains of a central loop on top of the crossbar where the spring would have been attached. The body of the brooch may have been made in two pieces, as the back plate of the brooch is straight and flat but the upper half of the bow, the 'knee', is formed by a projecting loop of metal which is joined to the back plate just below the head and again half way down the brooch, creating a sealed loop. The foot is worn but may have originally tapered to a small pedestal. The catchplate would have extended behind the foot at a right angle and had a perpendicular flat hook to hold the pin in place.

Hattatt (2000) illustrates several similar examples where the knee is a closed loop on page 335, fig.194, nos.1232-1233.The face of the brooch has moulded decoration on the crossbar and the looped knee, a transverse groove immediately below the knee and two grooves forming a diagonal saltire cross on the foot of the brooch. There are traces of silvering or tinning on the foot of the brooch. Hattatt dates this type of brooch from the 2nd century AD, with detailed descriptions in Brooches of Antiquity.

Bayley & Butcher (2004) illustrate a small knee brooch without the closed looped knee but otherwise similar in design and size on page 180, fig.154, no.T173A, which they state was widespread on civil and military sites in Britian and rare on the limes, or the Roman frontier, and was often enamelled or decorated with silver wire or foil.