Method of determining joint stress from sensor data
First Claim
1. A method of determining joint stress from sensor data comprising:
- obtaining a time series of sensor measurements from one or more sensors comprisinga first inertial sensor coupled to a first body part; and
,a second inertial sensor coupled to a second body part;
measuringone or more of position, orientation, or motion of said first body part of a subject using said first inertial sensor, andone or more of position, orientation, or motion of said second body part of said subject using said second inertial sensor;
whereinsaid first body part and said second body part are coupled to a body joint of said subject; and
,said first body part and said second body part lie on opposite sides of said body joint;
processing said time series of sensor measurements to generate one or more joint angle time series for said body joint, whereineach joint angle time series corresponds to a joint angle of said body joint; and
,each said joint angle of said body joint corresponds to a rotational degree of freedom of said body joint;
obtaining one or more ranges of motion for said body joint, whereineach range of motion of said one or more ranges of motion corresponds to said joint angle of said body joint; and
,said each range of motion of said one or more ranges of motion comprises an interval of joint angles that are within said range of motion;
determining one or more passive range time intervals when said one or more joint angle time series has a joint angle value that is outside a corresponding range of motion associated with said joint angle corresponding to a time period when said body joint is in a passive range of motion;
calculating a joint stress contribution using a computer during said one or more passive range of motion time intervals that are outside of an active range of motion;
combining said joint stress contribution across a plurality of movements by said subject during a period of time to calculate a joint fatigue;
calculating a recovery time for said subject from said joint fatigueorcalculating a workload limit for said subject during a future time period from said joint fatigue;
publishing or transmitting or displaying, or any combination thereof, using a computer, said recovery time or workload limit or both said recovery time and said workload limit.
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Accused Products
Abstract
A method of calculating the stress on a joint by determining when a joint angle is outside the normal range of motion for the joint. Applications include analysis of elbow joint stress for baseball pitchers, for example to mitigate the risk of injury to the ulnar collateral ligament (UCL). During a movement such as a baseball pitch, sensor data is collected to track the position, orientation, or motion of body segments; joint angles are derived from this sensor data. Joint angles are then compared to a range of motion, which may be measured for each individual. Joint stress contributions from movements that exceed the range of motion may be combined over time to calculate cumulative joint fatigue. This joint fatigue measure may for example be used for pitchers to quantify recovery periods (days off) and future workloads (such as maximum pitch counts).
12 Citations
10 Claims
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1. A method of determining joint stress from sensor data comprising:
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obtaining a time series of sensor measurements from one or more sensors comprising a first inertial sensor coupled to a first body part; and
,a second inertial sensor coupled to a second body part; measuring one or more of position, orientation, or motion of said first body part of a subject using said first inertial sensor, and one or more of position, orientation, or motion of said second body part of said subject using said second inertial sensor; wherein said first body part and said second body part are coupled to a body joint of said subject; and
,said first body part and said second body part lie on opposite sides of said body joint; processing said time series of sensor measurements to generate one or more joint angle time series for said body joint, wherein each joint angle time series corresponds to a joint angle of said body joint; and
,each said joint angle of said body joint corresponds to a rotational degree of freedom of said body joint; obtaining one or more ranges of motion for said body joint, wherein each range of motion of said one or more ranges of motion corresponds to said joint angle of said body joint; and
,said each range of motion of said one or more ranges of motion comprises an interval of joint angles that are within said range of motion; determining one or more passive range time intervals when said one or more joint angle time series has a joint angle value that is outside a corresponding range of motion associated with said joint angle corresponding to a time period when said body joint is in a passive range of motion; calculating a joint stress contribution using a computer during said one or more passive range of motion time intervals that are outside of an active range of motion; combining said joint stress contribution across a plurality of movements by said subject during a period of time to calculate a joint fatigue; calculating a recovery time for said subject from said joint fatigue or calculating a workload limit for said subject during a future time period from said joint fatigue; publishing or transmitting or displaying, or any combination thereof, using a computer, said recovery time or workload limit or both said recovery time and said workload limit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification