Testing the efficacy of motor analogies designed to promote safe landing by older adults who fall accidentally

INTERVENTION: Brief Name: Motor analogy Measurements and instrumentation: A 2D video camera (Canon, 25 frames per second) and 15 Delsys TrignoTM (Delsys Inc., Natrick, MA) inertial measurement units (IMU) will be used for data collection. The video camera will be positioned 3 meters from the side of the participants on a tripod (height 1.3 meters). The researcher will place 15 Delsys TrignoTM (Delsys Inc., Natrick, MA) inertial measurement unit (IMU) sensors on different body segments, described in the ‘sensor placement’ section. Acceleration data from the IMU sensors will be recorded at a frequency of 148.15 Hz using EMGworks Acquisition software (Version 4.5.4). A hand‐held dynamometer (MyoMeter, M550; range: 0‐50 kg) will be used to record the force applied when nudging each participant to fall. Procedure: Participants will be invited to a data collection session at the Human Performance Science Lab (TT 0.05) at the School of Health at the University of Waikato. Overall, the whole experiment will take approximately 1 hour and 30 minutes to 1 hour and 45 minutes. The procedure will be performed at the participant’s most comfortable pace and there will be an assistant standing by the participant at all times. The participant’s safety will be observed before performing each test and if there is any sign of potential harm the procedure will be immediately stopped. Furthermore, chairs will be placed close to the participants during all the procedures and they will be able to sit on them at any point during the experiment and participants will be provided with as many breaks as they want. 1. Sensor placement Fifteen small IMU sensors (dimension: 27 x 37 x 13 mm) will be attached on the following body segments using double sided tape: head, chest (aligned CONDITION: Fall related injuries; ; Fall related injuries Injuries and Accidents ‐ Fractures Injuries and Accidents ‐ Other injuries and accidents PRIMARY OUTCOME: Maximum acceleration (Impact force normalized by mass) of head by assessing IMU sensor data attached to participant's head[After receiving instructions and falling onto a soft surface at data collection session.] Maximum acceleration (Impact force normalized by mass) of chest by assessing IMU sensor data attached to participant's chest[After receiving instructions and falling onto a soft surface at data collection session.] Maximum acceleration (Impact force normalized by mass) of lower back by assessing IMU sensor data attached to participant's lower back[After receiving instructions and falling onto a soft surface at data collection session.] SECONDARY OUTCOME: Fracture risk ratio of wrists ; Fracture risk ratio is defined as the ratio of force at impact divided by the load necessary to cause a fracture. To calculate the force applied to the wrists, the acceleration data from the wrist sensors at impact will be multiplied by the scaling factors for the forearm mass (%mass) and then multiplied by 9.807 (convert g to m/s^2). Finally, the force applied to the participant’s wrist sensors will be divided by the load required to fracture the radius and femur bones based on cadaveric studies. [After receiving instructions and falling onto a soft surface at data collection session.] Fracture risk ratio of hips INCLUSION CRITERIA: • Age: 65 years and older • Able to stand without help for 1 minute • Able to walk without a walking aid for 6 meters • Able to communicate in English, with no psychiatric or neurological impairments prohibiting participation • Able to score above 3 on the Mini‐Cog test* • Able to pass the PARQ+ criterion** ; Fracture risk ratio is defined as the ratio of force at impact divided by the load necessary to cause a fracture. To calculate the force applied to the hips, the acceleration data from the hip sensors at impact will be multiplied by the scaling factors for the femoral head mass (%mass) and then multiplied by 9.807 (convert g to m/s^2). Finally, the force applied to the participant’s hip sensors will be divided by the load required to fracture the radius and femur bones based on cadaveric studies. [After receiving instructions and falling onto a soft surface at data collection session.] Maximum acceleration (Impact force normalized by mass) of hips by assessing IMU sensor data attached to participant's hips[After receiving instructions and falling onto a soft surface at data collection session.] Maximum acceleration (Impact force normalized by mass) of arms by assessing IMU sensor data attached to participant's arms[After receiving instructions and falling onto a soft surface at data collection session.] Maximum acceleration (Impact force normalized by mass) of hands by assessing IMU sensor data attached to participant's hands[After receiving instructions and falling onto a soft surface at data collection session.] Maximum acceleration (Impact force normalized by mass) of legs by assessing IMU sensor data attached to participant's legs[After receiving instructions and falling onto a soft surface at data collection session.] Maximum acceleration (Impact force normalized by mass) of thighs by assessing IMU sensor data attached to participant's thighs[After receiving instructions and falling onto a soft surface at data collection session.] Maximum acceleration (Impact force normalized by mass) of wrists by assessing IMU sensor data attached to participant's wrists[After receiving instructions and falling onto a soft surface at data collection session.] * The Mini‐Cog test (mini cognition test) has been validated for dementia screening; the score of 1 to 3 is considered “possibly impaired”, and a score above 3 is considered "probably normal” (Borson et al., 2003). ** The PARQ+ (physical activity readiness questionnaire) offers safe screening of older adults prior to engaging in exercise or physical activity (Cardinal & Cardinal, 1995; Cardinal, Esters, & Cardinal, 1996); it is sensitive to underlying conditions such as osteoporosis, cardiovascular conditions, respiratory disease, previous surgery, arthritis, chronic conditions, high blood pressure, back problem, etc.