AutoSave . Off) Joint Torque Lab - Home Assignment (2) - Compatibility Mode v Search Martina Stefinec MS X File Home Insert Draw Design Layout References Mailings Review View Help RCM Comments Editing Share & Cut Times New Romar ~ 12 ~ A" A Aa A Find AaBbC AaBb( AaBbCcI AaBbCcI AAD AaBbCCD Lol [ Copy S'c Replace Paste BIUvab X X A LA Heading 1 1 Heading 2 1 Normal 1 No Spac... Title Subtitle Dictate Sensitivity Editor Reuse Format Painter Select Files Clipboard Font Paragraph Styles Editing Voice Sensitivity Editor Reuse Files The table below lists and describes the various body segments and their approximate masses as a percent (%) of total body mass, and the relative position of each center of mass (COM) for each segment as a percent of total segment length from either the proximal or distal end of the segment. For example, if I want to know the approximate mass of the forearm for a person with a total body mass of 70kg, I would find the forearm segment below in the 2nd row, and then refer to the 3id column which indicates that the forearm is approximately 1.6% (0.0160) of total body mass. Therefore, the forearm mass for a 70kg individual should be 1.12kg (i.e. 70*0.0160). To find the distance (or position) from the proximal end of the segment (i.e. elbow joint) to the forearm's CoM. simply multiply forearm length (say 0.28 meters) by Roxxima for the forearm in the table below (0.43) to obtain a proximal CoM length of 0.12 meters (i.e. the forearm CoM is approx. 0.12m down the forearm from the elbow). Dempster's Body Segment Parameter Data for 2-D Studies' Segment Endpoints Seg. mass Centre of mass Radius of gyration name proximal to total mass /segment length segment length distal (P) (Rororimai) (Rafital) Kre Kproximal) Hand wrist axis to 0.0060 0.506 0.494 0.297 0.587 0.577 knuckle II third finger Forearm elbow axis to 0.0160 0.430 0.570 0.303 0.526 0.647 ulnar styloid Upper glenohumeral joint to ).0280 0.436 0.564 0.322 0.542 0.645 arm elbow axis Forearm elbow axis to 0.0220 0 682 .318 0.46 0.827 0.565 & hand alnar styloid Upper glenohumeral joint to 0.0500 .530 0.470 0.36 0.645 0.596 extremity knuckle II third finger Foot lateral malleolus to 0.0145 0.500 0.500 0.475 0.690 0.690 head metatarsal II Leg femoral condyles to 0.0465 0.433 0.567 0.302 0.528 0.643 medial malleolus Thigh greater trochanter to 0.1000 0.433 0.567 0.323 0.540 0.653 femoral condyles Leg femoral condyles to 0.0610 .606 0.394 0.416 0.735 0.572 & foot medial malleolus Lower greater trochanter to 0.1610 0.447 0.553 0.326 0.560 0.650 extremity medial malleolus Head C7-TI to ear canal 0.0810 1.000 0.000 0.495 1.116 0.495 Shoulder sternoclavicular joint to 0.0158 0.712 0.288 glenohumeral joint Thorax C7-TI to T12-L1 0 2160 0 820 0 180 Page 5 of 5 1 of 1291 words CX English (United States) Text Predictions: On ? Accessibility: Unavailable Focus + 100% 10 N 41.F Cloudy 20:5 24.3.2023.AutoSave . Off) Joint Torque Lab - Home Assignment (2) - Compatibility Mode v Search Martina Stefinec MS X File Home Insert Draw Design Layout References Mailings Review View Help RCM Comments Editing Share & Cut Times New Romar ~ 12 ~ A" A Aa A Find AaBbC AaBb( AaBbCcI AaBbCcI AAD AaBbCCD Lol [ Copy S'c Replace Paste BIU ab X X A LA 1 Heading 1 1 Heading 2 Normal 1 No Spac... Title Subtitle Dictate Sensitivity Editor Reuse Format Painter Select Files Clipboard Font Paragraph Styles Editing Voice Sensitivity Editor Reuse Files Hand wrist axis to 0.0060 0.506 0.494 0.297 0.587 0.577 knuckle II third finger Forearm elbow axis to 0.0160 0.430 0.570 0.303 0.526 0.647 ulnar styloid Upper glenohumeral joint to 0.0280 0.436 0.564 0.322 0.542 0.645 arm elbow axis Forearm elbow axis to 0.0220 0.682 0.318 0.468 0.827 0.565 & hand alnar styloid Upper glenohumeral joint to 0.0500 0.530 0.470 0.368 0.645 0.596 extremity knuckle II third finger Foot lateral malleolus to 0.0145 0.500 0.500 0.475 0.690 0.690 head metatarsal II Leg femoral condyles to 0.0465 0.433 0.567 0.30 0.528 0.643 medial malleolus Thigh greater trochanter to 0.1000 0.433 0.567 0.323 0.540 0.653 femoral condyles Leg femoral condyles to 0.0610 0.606 0.394 0.416 0.735 0.572 & foot medial malleolus Lower greater trochanter to 0.1610 0.447 0.553 0.326 0.560 0.650 extremity medial malleolus Head C7-T1 to ear canal 0.0810 1.000 0.000 0.495 1.116 0.495 Shoulder stemnoclavicular joint to 0.0158 0.712 0 288 glenohumeral joint Thorax C7-T1 to T12-L1 0.2160 0.820 0.180 Abdomen T12-L1 to L4-L5 0.1390 0.440 0.56 Pelvis L4-L5 to trochanter 0.1420 .105 0.895 Thorax C7-T1 to L4-L5 ).3550 0.630 0.37 & abdomen Abdomen T12-L1 to 0.2810 0.270 0.730 & pelvis greater trochanter Trunk greater trochanter to 0.4970 .495 0.505 0.406 0.640 0.648 glenohumeral joint Trunk greater trochanter to 0.5780 0.660 0.340 0.503 0.830 0.607 & head glenohumeral joint Head, arms greater trochanter to 0.6780 .626 0.374 0.496 0.798 0.621 & trunk glenohumeral joint Head, arms greater trochanter to 0.6780 1.142 -0.142 0.903 1.456 0.914 & trunk midrib Page 5 of 5 1 of 1291 words CX English (United States) Text Predictions: On ?Accessibility: Unavailable Focus + 100% 20:52 10 N 41.F Cloudy 24.3.2023.AutoSave . Off) Joint Torque Lab - Home Assignment (2) - Compatibility Mode v Search Martina Stefinec MS X File Home Insert Draw Design Layout References Mailings Review View Help RCM Comments Editing Share & Cut Find Times New Romar ~ 14 ~ A" A Aa A AaBbC AaBb( AaBbCcI AaBbCcI Aab AaBbCCD Lol Paste [ Copy S'c Replace 1 Heading 1 1 Heading 2 1 Normal 1 No Spac... Title Subtitle Dictate Sensitivity Editor Reuse Format Painter BIUab X X A LA Select Files Clipboard Font Paragraph Styles Editing Voice Sensitivity Editor Reuse Files | ~ EXSC 3700 Joint Torque Lab Lab Preparation Video: https://youtu.be/g1QnZILWor4 Purpose: The purpose of this lab is to examine the effects of variations in arm position on the external and internal torques, and corresponding deltoid muscle force that occur during a static contraction. Rationale: Changes in the position of a limb, and changes in the load applied to a limb, are both factors that influence the magnitude of the external joint torques that act on a limb. In order for a static position to be held (i.e. no movement) the internal torque generated through muscle contraction must equal the external torque. Typically the muscle "moment arm", involved in the calculation of the internal torque, is very short. Thus, in order to produce an internal torque that is of sufficient magnitude to equalize the external torque (or torques), the muscle force must be very great. Determination of such muscle force is important for a thorough understanding of the stresses that are placed on muscles, tendons, and joints. Equipment: Measuring Tape, Dempster's Anthropometric Tables (see last page), Calculator Procedural Steps: 1. Complete Part I on the next page. 2. Next, select one member from your group to serve as the test subject. Record their total body mass (kg) as "A" in Part II below. Then, have the subject stand and position their arm at 90 of abduction. 3. Estimate the distance (in meters) from the acromion process to the distal deltoid muscle insertion on the humerus by measuring the length of the deltoid muscle from the acromion to where it "dips" in toward the arm. This measurement provides both an estimate of deltoid muscle fiber length and deltoid muscle moment arm ("B"). Deltoid muscle moment arm for "B" in Part II. 4. Measure the arm length (from the acromion process to the end of the fist - 2nd knuckle). This is "C" in Part II. Page 1 of 5 1291 words x English (United States) Text Predictions: On ?Accessibility: Unavailable Focus + 100% 10 N 41'F Cloudy At HRV 20:46 24.3.2023.AutoSave . Off) Joint Torque Lab - Home Assignment (2) - Compatibility Mode v Search Martina Stefinec MS X File Home Insert Draw Design Layout References Mailings Review View Help RCM Comments Editing Share & Cut Find Times New Romar ~ 14 ~ A" A Aa Ap AaBbC AaBb( AaBbCcI AaBbCcI Aab AaBbCCD Lol Paste [ Copy S'c Replace BIUab X X A LA 1 Heading 1 1 Heading 2 1 Normal 1 No Spac... Title Subtitle Dictate Sensitivity Editor Reuse Format Painter Select Files Clipboard Font Paragraph Styles Editing Voice Sensitivity Editor Reuse Files | ~ 3. Estimate the distance (in meters) from the acromion process to the distal deltoid muscle insertion on the humerus by measuring the length of the deltoid muscle from the acromion to where it "dips" in toward the arm. This measurement provides both an estimate of deltoid muscle fiber length and deltoid muscle moment arm ("B"). Deltoid muscle moment arm for "B" in Part II. 4. Measure the arm length (from the acromion process to the end of the fist - 2nd knuckle). This is "C" in Part II. 5. Calculate the following using Dempster's body segment parameters table (last page): a. distance from the acromion process to the Center of Mass (CoM) of the upper extremity. (4th column in the outlined section of the table) - this is "D" in Part II. b. mass of the upper extremity. (using the 3"d column in the outlined section of the table) - "E" in Part II. 6. Calculate the force of gravity acting on the arm's mass ("F" in Part II) by taking the arm's mass (E) and incorporating gravity to obtain force in Newtons. For "G" in Part II, convert the weight of the 101b dumbbell from pounds to Newtons. 7. Utilizing your setup from Part I and the data from Part II, complete the calculations described in Part III to determine both internal and external torques, as well as muscle forces (N), for both the 90 and 45 positions. 8. Finally, complete the discussion questions in Part IV. Dout I Deahlam Catan Page 1 of 5 1291 words DX English (United States) Text Predictions: On ?Accessibility: Unavailable " Focus + 100% 41.F Cloudy 20:46 10 N At HRV 24.3.2023.AutoSave . Off) Joint Torque Lab - Home Assignment (2) - Compatibility Mode v Search Martina Stefinec MS X File Home Insert Draw Design Layout References Mailings Review View Help RCM Comments Editing Share & Cut Find Times New Romar ~ 14 ~ A" A Aa A AaBbC AaBb( AaBbCcI AaBbCcI Aab AaBbCCD Lol Paste [ Copy S'c Replace BIUab X X A LA 1 Heading 1 1 Heading 2 1 Normal 1 No Spac... Title Subtitle Dictate Sensitivity Editor Reuse Format Painter Select Files Clipboard Font Paragraph Styles Editing Voice Sensitivity Editor Reuse Files Part II. Data A. 74 _ total body mass (kg) B. 0.06 _ muscle moment arm (m) C. 0.27 arm length (m) D. 0.53 distance from the acromion process to the COM of the arm (m) E. 3.7 arm mass (kg) F. _36.3_ force of gravity on the arm's mass (N) G. _44.4_ force of the 101b weight (N) Part III. Calculating Torques and Muscle Force 1. Using the information above, calculate the total external torque applied to the shoulder joint while the arm is holding a 101b weight at 90 degrees of abduction. 2. Now calculate the total external torque applied to the shoulder joint while the arm is holding a 101b weight at 45 degrees of abduction. Page 2 of 5 1291 words DX English (United States) Text Predictions: On A? Accessibility: Unavailable Focus + 100% 20:47 10 N 41.F Cloudy At HRV 24.3.2023.AutoSave . Off) Joint Torque Lab - Home Assignment (2) - Compatibility Mode v Search Martina Stefinec MS X File Home Insert Draw Design Layout References Mailings Review View Help RCM Comments Editing Share & Cut Times New Romar ~ 14 ~ A" A Aa Ap EVEEVENT Find AaBbC AaBb( AaBbCcI AaBbCcI Aab AaBbCCD Lol Paste [ Copy S'c Replace BIUvab X X A LA 1 Heading 1 1 Heading 2 1 Normal 1 No Spac... Title Subtitle Dictate Sensitivity Editor Reuse Format Painter Select Files Clipboard Font Paragraph Styles Editing Voice Sensitivity Editor Reuse Files Part III. Calculating Torques and Muscle Force 1. Using the information above, calculate the total external torque applied to the shoulder joint while the arm is holding a 101b weight at 90 degrees of abduction. 2. Now calculate the total external torque applied to the shoulder joint while the arm is holding a 101b weight at 45 degrees of abduction. 3. Taking the net external torque from #1 above, and with what you know about the internal torque, estimate the deltoid force that is required to maintain the 90 degree shoulder abduction angle while holding the 101b weight. 4. Taking the net external torque from #2 above, and with what you know about the internal torque, estimate the deltoid force that is required to maintain the 45 degree shoulder abduction angle while holding the 101b weight. Page 3 of 5 1291 words DX English (United States) Text Predictions: On ?Accessibility: Unavailable Focus + 100% 20:47 10 N 41'F Cloudy At HRV 24.3.2023