moving this from the wiki:

This shield specialization is currently not working as intended.

Character, your Shield Specialization training is as follows:

Skill name Mnemonic Ranks
Tower Shield Focus tfocus 5
Shield Bash bash 5
Shield Push push 5
Prop Up prop 1
Block the Elements eblock 1
Protective Wall pwall 2
Shield Strike strike 1

A shrickhen tries to bite you!
AS: +373 vs DS: +279 with AvD: +7 + d100 roll: +81 = +182
... and hits for 8 points of damage!
Deft slash across chest draws blood!
You take a deep breath.

A shrickhen screams furiously and points at you!
A wave of dark ethereal ripples moves outward from a shrickhen.
You are buffeted by the dark ethereal waves, and knocked to the ground.
You are pinned in place, unable to move.
Roundtime: 10 sec.

A shrickhen claws at you!
AS: +379 vs DS: +229 with AvD: +7 + d100 roll: +32 = +189
... and hits for 13 points of damage!
Minor puncture to the back.

Maybe someone had an old tower shield that had never been converted from medium?