PWS

*barak- - chest, thorax (SED I No. 38)

Rather to be separated from *bi/ark- ‘knee’ (SED I No. 39). Note Akk. ‘lap’ in birku, burku [CAD b 255] given as a second meaning; this rather developed from the main meaning ‘knee’ (see *bi/ark­- ‘knee’), though it may also ensue from Sem. *barak-­ ‘chest’.

Arabic
bark- - skin of the belly of the camel and of the portion of the breast next to it; male breast (BK 1 116, Lane 193)
The additional meaning related to kneeling appears to be due to contamination with *bi/ark­ ‘knee’.
Amharic
bərakkʷa - shoulder blade, bone of a cow’s foreleg (AED 886)
With labialization of -kk- under the influence of b-? While the first meaning rather relates to ‘chest’, the second may continue *bi/ark- ‘knee’ as well.
Mehri
bərk - in, at, inside, among (ML 52)
Probably related. Leslau reasonably thinks related to Soq. bérak ‘poitrin’ [LS 95]; for a similar semantic development cf. Mhr. mən ḥəḳ ‘inside’ (prep.) [JM 175] (and related MSA forms) ∼ Sem. *ḥi/aḳ(ʷ)-­ ‘hip, loin, lap’, No. 113.
Harsusi
berk - in, into (HL 19)
Probably related.
Soqotri
bérak - poitrine (LS 95)