"Resisting arrest, the woman is alleged to have tried to bite one of the officers at which time two of our staff took the woman to the ground to facilitate applying handcuffs.''
Police believe at this time the woman suffered a cut to her left cheek when her glasses made contact with the ground and her face.
A passing ambulance was flagged down and her injuries were treated.
The woman was eventually taken back to Hamilton central police station when it was noted she had suffered a dislocated elbow.
She was taken to Waikato Hospital to have her injuries attended.
Mr van der Velde said there were "significant discrepancies'' in the claims made by the woman and statements taken from officers and supermarket staff at the scene.
The woman has been charged with resisting arrest and disorderly behaviour and is yet to appear in court.
The matter is under internal investigation and has been referred to the Independent Police Complaints Authority.
Mr van der Velde said his staff acted responsibly and appropriately at the time.