An apparatus constructed to pull a strand of hair, the apparatus comprising: a frame having a longitudinal axis (A 1 ) and a first end;a first leg , a second leg , and a third leg extending from the first end of the frame the third leg spaced apart from the first and second legs; wherein the first, second, and third legs (14, 16, and 30), respectively, are integrally coupled to the frame , or releasably coupled to the frame , or some combination thereof; wherein the third leg is movable linearly relative to the frame ; wherein the third leg comprises a rod having external threads and an end distal to the frame , wherein the apparatus includes a knob rotatably coupled to the frame , wherein the knob includes internal threads that are configured to receive the rod and engage the external threads of the rod ; a control system comprising a processor to execute a plurality of pulling profile instructions stored in a memory ; a linear actuator operatively coupled to the control system and constructed to move linearly along the longitudinal axis (A 1 ) relative to the frame , the linear actuator having a distal end ; a load cell coupled to the linear actuator , wherein the load cell is positioned between an upper portion and a lower portion of the actuator ; and a gripper coupled to the distal end of the linear actuator , the gripper constructed to grip a strand of hair; wherein when one or more of the plurality of pulling profile instructions stored in memory are executed by the processor , the control system causes the linear actuator to retract along the longitudinal axis (A 1 ), applying a pulling force to a strand of hair gripped by the gripper ; and wherein the load cell is configured to measure the pulling force. a frame having a longitudinal axis (A 1 ) and a first end;a first leg , a second leg , and a third leg extending from the first end of the frame the third leg spaced apart from the first and second legs; wherein the first, second, and third legs (14, 16, and 30), respectively, are integrally coupled to the frame , or releasably coupled to the frame , or some combination thereof; wherein the third leg is movable linearly relative to the frame ; wherein the third leg comprises a rod having external threads and an end distal to the frame , wherein the apparatus includes a knob rotatably coupled to the frame , wherein the knob includes internal threads that are configured to receive the rod and engage the external threads of the rod ; a control system comprising a processor to execute a plurality of pulling profile instructions stored in a memory ; a linear actuator operatively coupled to the control system and constructed to move linearly along the longitudinal axis (A 1 ) relative to the frame , the linear actuator having a distal end ; a load cell coupled to the linear actuator , wherein the load cell is positioned between an upper portion and a lower portion of the actuator ; and a gripper coupled to the distal end of the linear actuator , the gripper constructed to grip a strand of hair; wherein when one or more of the plurality of pulling profile instructions stored in memory are executed by the processor , the control system causes the linear actuator to retract along the longitudinal axis (A 1 ), applying a pulling force to a strand of hair gripped by the gripper ; and wherein the load cell is configured to measure the pulling force. <EOS>