Another mishap consequence of having volume mimicking magic pockets.Plus almost every noob seems to just cram every miscellaneous object down their pants and thinks it won’t have any repercussions.
Check your volume and weight and if anything is over the amount of either or both. Then that is your problem.
Not blocking just means you’ll take the full damage to wherever rather than partial damage to your arms. If your arms are armored, it shouldn’t be a problem since the armor will soak it.