Physical therapy clinics are staffed with physical therapists and therapy equipment. Physical therapy involves the interaction between therapist, patients or clients, other health care professionals, families, care givers, and communities in a process where movement potential is assessed and diagnosed and goals are agreed upon. Physical therapy is performed by a therapist and sometimes services are provided by a physical therapist assistant (PTA) acting under their direction. Physical therapists and occupational therapists often work together in conjunction to provide treatment for patients. In some cases, physical rehabilitation technicians may provide physiotherapy services.