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Matsumura U1, Lee Y1, Kai A2, Numata M3, Tsurusaki T4
1Nagasaki University Graduate School of Biomedical Science, Health Science, Nagasaki City, Japan, 2Kuroki Memorial Hospital, Rehabilitation, Oita City, Japan, 3Nagasaki North Hospital, Rehabilitation, Nagasaki City, Japan, 4Nagasaki University, Institution of Biomedical Science, Nagasaki City, Japan
Background: In clinical fields, Manual Muscle Testing (MMT) and Hand Held Dynamometry (HHD) are often used as evaluate of muscle strength. However, these are merely evaluating in isometric contraction in a certain position. Actually, muscle strength during motions must be considered as joint moment, which means forces to rotate a segment around joints. For measurement of joint moment, a 3-dimensional motion analysis device and force plate are required. However, those are too expensive and complicated to use in clinical fields. In the first place, in addition to muscle contractions,the occurrence of joint moment involves the gravity and passive elements. So they are necessary to correct. Furthermore, a surface electromyogram (SEMG) can not only muscle activity record but also can separate the passive elements. Also, because the length of the muscle varies depending on the joint angle, it is necessary to consider angle variations.Therefore, the hypothesis that joint moment can be estimated by using angular variations of limbs (with reference to the gravity) and SEMG is established.
Purpose: To verify above hypothesis and suggest how to estimate joint moment during motions.
Methods: Subjects were ten young adults (five males and five females) without orthopedic problems. Three types of motion, half squat, knee joint bending with one leg standing, walking were performed for the subjects. Each motion was performed at three different speeds. SEMG data were collected from quadriceps femoris, hamstrings, tibialis anterior and gastrocnemius. Angle variance of limbs with reference to the gravity was recorded using the 9 axis motion sensor. In addition, actual joint moments were measured by using the 3-dimensional motion analysis device and force plate. All data were processed to be 30 Hz sampling and synchronized. Angle information and SEMG integral values were defined as explanation variables, so as to obtain the multiple regression model with the actual joint moments as a target variable. Then the correlation between actual and estimated joint moments were examined for each subject.
Results: The average values of the correlation coefficient for each type of motion were as follows. At half squat, though Ankle Joint Moment (AJM) was a moderate correlation (0.60±0.20), Knee Joint Moment (KJM) was almost complete (0.95±0.01). In the knee joint bending, AJM and KJM both showed high correlation (AJM; 0.92±0.02 KJM; 0.83±0.16). Even walking, relatively high correlation were obtained in both AJM and KJM (AJM; 0.82±0.05 KJM; 0.75±0.07). In all cases, p values were less than 0.001.
Conclusion(s): The hypothesis that joint moment can be estimated using the angular changes of limbs and SEMG has been proved. The results of this study include that estimation of time-dependent change of joint moment. Therefore, it was suggested that evaluations of joint moment during motions could be possible without using expensive and complicated devices.
Implications: By quantifying the muscle power required for the motion, it would be possible to apply as an objective indicator in programming. Also, it would be applicable in movements which are needed objective evaluation of muscle power during motions, such as athletic complicated movements and crawling.
Keywords: Joint moment, estimation, angular change
Funding acknowledgements: There is no conflict of interests related to this research.
Purpose: To verify above hypothesis and suggest how to estimate joint moment during motions.
Methods: Subjects were ten young adults (five males and five females) without orthopedic problems. Three types of motion, half squat, knee joint bending with one leg standing, walking were performed for the subjects. Each motion was performed at three different speeds. SEMG data were collected from quadriceps femoris, hamstrings, tibialis anterior and gastrocnemius. Angle variance of limbs with reference to the gravity was recorded using the 9 axis motion sensor. In addition, actual joint moments were measured by using the 3-dimensional motion analysis device and force plate. All data were processed to be 30 Hz sampling and synchronized. Angle information and SEMG integral values were defined as explanation variables, so as to obtain the multiple regression model with the actual joint moments as a target variable. Then the correlation between actual and estimated joint moments were examined for each subject.
Results: The average values of the correlation coefficient for each type of motion were as follows. At half squat, though Ankle Joint Moment (AJM) was a moderate correlation (0.60±0.20), Knee Joint Moment (KJM) was almost complete (0.95±0.01). In the knee joint bending, AJM and KJM both showed high correlation (AJM; 0.92±0.02 KJM; 0.83±0.16). Even walking, relatively high correlation were obtained in both AJM and KJM (AJM; 0.82±0.05 KJM; 0.75±0.07). In all cases, p values were less than 0.001.
Conclusion(s): The hypothesis that joint moment can be estimated using the angular changes of limbs and SEMG has been proved. The results of this study include that estimation of time-dependent change of joint moment. Therefore, it was suggested that evaluations of joint moment during motions could be possible without using expensive and complicated devices.
Implications: By quantifying the muscle power required for the motion, it would be possible to apply as an objective indicator in programming. Also, it would be applicable in movements which are needed objective evaluation of muscle power during motions, such as athletic complicated movements and crawling.
Keywords: Joint moment, estimation, angular change
Funding acknowledgements: There is no conflict of interests related to this research.
Topic: Human movement analysis; Outcome measurement
Ethics approval required: Yes
Institution: Nagasaki University
Ethics committee: Ethics Committee of the Graduate School of Medical Facilities
Ethics number: Approval number 18061429
All authors, affiliations and abstracts have been published as submitted.
