In-flight Demonstration of Portable Load Monitoring Devices-Phase I: XSENS ForceShoeTM (Force Shoes) - 11.12.14
ISS Science for Everyone
Science Objectives for Everyone
Crew members on the International Space Station need to exercise regularly to maintain their health. Because it provides resistance (weight) training, the Advanced Resistive Exercise Device (ARED) is a critical component of the crew's exercise program, but it lacks reliable instrumentation for measuring exercise loads. Force Shoes evaluates a new shoe system that can measure exercise loads on the ARED, providing important data for current and future human research experiments in space.
Science Results for Everyone
OpNom Force Shoes
Johnson Space Center, Human Research Program, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
Earth Benefits, Scientific Discovery, Space Exploration
ISS Expedition Duration
March 2014 - September 2015
Previous ISS Missions
- Due to multiple issues associated with the load monitoring system of the Advanced Resistive Exercise Device (ARED) on the International Space Station (ISS), load data for exercise performed on that device is not provided. Force Shoes is an engineering evaluation of the XSENS ForceShoe™ system as a potential alternate method to measure loads imparted by the ARED.
- A series of static and dynamic load measurements on ARED are performed by ISS crew members. A static load measurement on the ISS treadmill is also included in order to compare the load data from the XSENS ForceShoe™ system with the ISS treadmill load sensors. Researchers use the measurements made by the XSENS ForceShoe™ system to quantify exercise load data, which is needed for support of current and future human research experiments.
The Advanced Resistive Exercise Device (ARED) instrumentation system was designed to provide exercise data to support real-time training and fulfill medical requirement reporting. The instrumentation was also meant to provide ground-based researchers with data to enhance training programs, better understand the connection between current on-orbit exercise prescriptions and musculoskeletal health, and aid in the design of future exercise devices. Due to unanticipated interruption to the mechanical performance of the force platform, reliably accurate data has not been available since ARED installation. Due to a damaged power cable port, no data has been recorded through the ARED instrumentation system since mid-2011. As a result, NASA’s Human Research Program (HRP) has been carrying a risk (“Inability to obtain accurate, synchronized data from ISS exercise hardware for use in HRP studies”) since August 2010 which was elevated to a Top Program Risk as of April 2012. Additionally, an ISS watch item (“Inability to access accurate ARED data used in HRP exercise research protocols”) has been carried since 2011.
ARED load data is integral to many ongoing, and future, HRP and International Partner (IP) funded studies. For example, the joint ESA/NASA ARED Kinematics study cannot start until accurate ground reaction force data can be recorded. Future HRP countermeasure studies also need to understand the contribution that ARED loading makes to health outcomes, particularly to inform the design of advanced exercise countermeasure devices. As result, HRP has funded the preliminary evaluation of portable load monitoring devices and technology demonstrations on the ISS.
The XSENS ForceShoe™ has gone through ground and parabolic flight evaluation, and has been selected as the first portable load monitoring device for a hardware demonstration aboard the ISS.
Up to four crew members participate in this engineering evaluation of the XSENS ForceShoes™ in order to assess the hardware system as a method to collect the required load data. Following analysis of the in-flight data, a recommendation on the future use of the XSENS ForceShoe™ for operational and research use can be made.
Accurate and reliable load data from the Advanced Resistive Exercise Device (ARED) is integral to several current and future human spaceflight experiments, as well as for the countermeasures community. The ARED load-measurement system, which records how much resistance exercise crew members perform, is not operable. Force Shoes uses the XSENS ForceShoe™ system as an alternate method for measuring the loads provided by ARED.
The Force Shoe evaluation provides athletic trainers, health and exercise scientists, and physicians with new data that can improve their strength-training efforts. Results from exercises performed on long-duration space missions, where bone and muscle are in a weakened state due to the lack of gravity, also benefit people on Earth with limited mobility, those in physical therapy, or those evaluating human movement in confined spaces.
Up to four subjects participate in this investigation in order to gather sufficient representative data to assess the fidelity of the hardware for use in current and future human research experiments.
Up to four sessions per subject may be scheduled to collect a series of load measurements on ARED in order to obtain a sufficient number of data points for analysis of the Force Shoe performance. During each session, static and dynamic data is collected in different ARED configurations: ARED Main Exercise Bar in the high position, ARED Main Exercise Bar in the low position, and use of the ARED exercise cable. Dynamic data collection during a subset of exercises typically performed on ARED follows. Private high-definition video recording of each session is required in order to correlate Force Shoe data with crew member actions. This video is downlinked after each session. Privatized, real-time video in standard-definition is also required for the first performance of this session with each subject to assist the crew real-time and verify completion of objectives.
Two inflight calibration sessions (no more than one per subject) are also required. A series of static load measurements on the T2 treadmill using different numbers of French clips with the bungees are collected. During the T2 session, the treadmill belt must be programmed to 0 mph. The data collected via the Force Shoes and the T2 load cells are downlinked and compared against each other by ground personnel. As with the ARED sessions, private high-definition video recording with later downlink (to correlate Force Shoe data with crew member actions) is required. Privatized, real-time video in standard-definition is also required to assist the crew real-time and verify completion of objectives.
A minimum of 7 days (preferably 14 days) is required between T2 and ARED sessions for a given subject, as well as between the first and second ARED sessions for a given subject, to allow the Investigation Team to evaluate the data and ensure the shoes are operating properly before the next data collection session is performed (there is no minimum separation for subsequent ARED sessions). Additionally, Force Shoes ARED sessions should not be scheduled during the first 30 days of a crew member's stay on-orbit to allow sufficient time for adaptation of lift technique to the microgravity environment and familiarization with the loads imparted by the on-orbit exercise equipment before the first use of the Force Shoes.
During the T2 calibration session, the crew member sets up the Force Shoe hardware by connecting the Force Shoes Wireless Receiver to a Space Station Computer (SSC), installing batteries into the Force Shoes Unit (router), and connecting the Force Shoes to the Force Shoes Unit (router) via the Force Shoes Comm Cables. The Force Shoes must be allowed to warm-up for a minimum of 10 minutes, during which the crew member watches a short video to describe the crew activity and setup the camera. Before the T2 session, the Biomedical Engineer (BME) uplinks a software profile in which the treadmill belt is programmed to 0 mph while collecting force data. To start, the crew member zeroes the force shoes, and takes a zero-load measurement with the Force Shoes in a free float environment. Next, the crew member dons the Force Shoes and takes another zero load measurement while wearing the shoes in a free float environment. The crew member then stands on T2 while wearing the Force Shoe hardware system and transmitting data to the ISS server. The crew member is tethered to the treadmill using a set of bungees, per nominal operating procedures. The crew member stands motionless on the treadmill for a few seconds to collect static load data on the Force Shoes, and on T2. Afterwards, a French clip is added in-line between the bungees and the crew member-worn harness, and another static load measurement is taken. The process is repeated until there is no contact between the Force Shoes and the treadmill. The data from T2 is compared to the Force Shoe data after downlink by the Orbital Communications Adapter (OCA).
Once the crew member is scheduled to perform an ARED data collection session with the Force Shoes, an ARED cylinder evacuation activity is scheduled prior to and within 24 hours of a Force Shoe data collection. During the ARED data collection session, the crew member sets up the Force Shoe hardware by connecting the Force Shoes Wireless Receiver to an SSC, installing batteries into the Force Shoes Unit (router), and connecting the Force Shoes to the Force Shoes Unit (router) via the Force Shoes Comm Cables. The Force Shoes are allowed to warm-up for a minimum of 10 minutes, during which the crew member watches a short video to describe the crew activity and setup the camera. Before the ARED sessions, the BME uplinks an exercise prescription similar to that used for regular ARED exercise sessions, but instructs the crew member to collect static load data. To start, the crew member zeroes the force shoes, and takes a zero-load measurement with the Force Shoes in a free float environment. Next, the crew member dons the Force Shoes and takes another zero load measurement while wearing the shoes in a free float environment. The crew member configures ARED with the Main Exercise Bar in the low position, and with the load at the lowest setting for that session. The crew member then lifts the bar off of the stops for ten seconds. The crew member then increases the load by 25-50 lbs, and lifts the bar off of the stops three times for ten seconds each time. This is repeated incrementally until the maximal load for the sessions is reached. The load is then decreased incrementally until the minimal load for the session is reached. Finally, the load is increased incrementally for a second time until the maximal load for the session is reached, so that three sets of data are collected for each load. Next, the crew repeats the process with the ARED Main Exercise Bar at the high position, and with the ARED exercise cable configured for bicep curls. Finally, the crew member proceeds with performing a subset of regular ARED exercises with the Force Shoes donned, in order to collect dynamic data while performing regular ARED exercises.
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