SP2604 Methodology Assignment
Introduction
The purpose of this laboratory report is to assess your understanding of several concepts of angular kinematics and angular kinetics taught in SP2604 module.
Motion data from a person walking over ground (gait) is being provided in the attached Excel workbook. For the analysis of the participant’s gait, you are required to calculate several kinematic and kinetic parameters, in addition to parameters related to the biomechanical properties of triceps surae muscle-tendon unit, as instructed in the Methodology and Results sections below.
Use all information available to you (e.g., data in Excel sheets, instructions provided under Methodology and Results, lecture slides, images, and laboratory notes) to write a succinct and accurate “Methods” and “Results” section.
SP2604 Methodology Assignment
SP2604 Methodology Assignment
Methodology – You are required to include the following information in a Methodology section.
A methodology section, usually contains 4 parts: Participant(s), Equipment & Material, Protocol (Procedure), Data Processing & Analysis.
- Incorporate information provided below in relevant sections (participant(s), equipment & material, protocol, and data processing & analysis) to write the Methodology section.
- To each sub-section above, add information which should be retrieved and/or calculated from data available to you, and/or biomechanics textbooks (e.g., add equation used in the calculation of instantaneous velocity from a textbook and cite the source) in order to complete the Methodology section.
- Avoid using bullet points when writing Methodology. The section should be written as an essay.
Incorporate Figure 1 (below) in your report in a relevant section.
Figure 1. 25 light-reflecting markers were mounted on the pelvis and lower limbs during the study. Early stance of the left foot on force plate 1 (FP1) is illustrated; participant was propelling herself forward.
SP2604 Methodology Assignment
The following information about the participant should be incorporated into the Participant sub-section:
- Female;
- Healthy;
- Age = 50 years;
- Mass = 74.3 kg;
- Height = 1.725 m;
- Shank length (distance measured between the knee joint centre and lateral malleolus): 35 cm
- Triceps Surae muscle-tendon unit length: 37 cm;
The following information should be incorporated into the Equipment & Material sub-section:
- 8-camera Qualysis motion capture system;
- Sampling Frequency of the cameras: 150 frames/sec (Hz);
- 5 Kistler force plates identified as FP1-FP5 in Figure 1 above;
- Sampling Frequency of the force plates: 150 frames/sec (Hz);
- A 25-marker set to identify major segments and joints of the lower limbs
In addition to the information above, comment on:
o Laboratory coordinate system – include information about the vertical and the two horizontal axes. Important: Identify along what axis the participant was walking.
The following information should be incorporated into the Protocol (Procedure) sub-section:
Data collection period: 2.48 seconds
In addition to information above, add the following to the Protocol sub-section:
o Instructions to the participant (i.e., what instructions could have been given to the participant?)
o Comment on the direction of movement (e.g. toward laboratory origin or away from it?).
SP2604 Methodology Assignment
The following information should be incorporated into the Data Processing & Analysis sub-section:
- Data provided in the Excel workbook belongs to the Left lower limb.
- Sheet called (Angles), contains information about joint (ankle, knee, hip) rotations (angles) around the x, y, and z axes. Note. Scroll down the page to see all data.
- Sheet called “Moments” contain moments of force (torques) about the ankle, knee and hip joints around the 3 axes (x,y,z) for the Left lower limb. Note. Do not delete rows 3-13 which contain no information. Scroll down the page to see all data.
- One stride of the Left lower limb (from left heel strike to left heel strike) happened between rows 168 and 331 of the Excel sheet and should be used for this laboratory report.
- Stance phase of the stride above contained 99 rows (Excel rows 168-266) – 60% of the stride length.
- Swing phase of the stride above contained 65 frames (Excel rows 267-331) – 40% of the stride length.
Kinematic and kinetic data of the Left lower limb joints for one stride (Excel rows 168-331) in the sagittal plane are of interest to this laboratory report, and all calculations and plots required should use the Excel rows above.
SP2604 Methodology Assignment
In the Methodology section, add information on how the following parameters were decided and/or calculated (provide relevant citations from biomechanics textbooks when presenting formulae where required):
- The two axes defined the sagittal plane for the stride above
- Stride length (for the one stride above)
- Instantaneous Angular Velocity and Acceleration values for the Ankle, Knee and Hip joints
- Phase Plots for Ankle, Knee only
- Ankle-Knee Angle-Angle diagram
- Ankle-Knee Continuous Relative Phase (CRP)
- Triceps Surae muscle-tendon unit length changes during the stride above
- Linear displacement of the lateral malleolus during rotation of the knee joint through its range of motion for the stride above
- Power of the Ankle, Knee, Hip joints in the sagittal plane for the stride above
SP2604 Methodology Assignment
In Summary, your methodology should describe how the requested parameters 1-9 above were retrieved/calculated.
SP2604 Methodology Assignment
Methodology – 30 Marks (30%)
3 marks for referring to each of the 9 points above and providing relevant information for calculating parameters requested (27 marks). Incorporation of the 4 parts requested and cohesiveness of the written section (3 marks).
Results – You are required to include the following information in a Results section.
- Calculate and Show your work in separate Excel sheets identified.
- Step by step, report results in the Results section, and refer to the relevant Excel sheet (where work is shown and saved).
- All calculations must be in the Excel workbook in the relevant sheets.
- All reports must be in the Results sections (Word or PDF document) under relevant subheadings.
- Avoid using bullet points when writing Results section. Instead, provide relevant subheadings (e.g., subheadings that match the Excel sheets names). The section should be written as an essay.
SP2604 Methodology Assignment
According to the information provided in the Methodology, Results section should at least contain the following:
Plot of the Ankle, Knee, Hip joints
o In the sheet called “Angles”:
i. Plot Ankle, Knee and Hip joints rotation in the sagittal plane for the stride above;
ii. For each plot, provide Axes title and use appropriate units for each axis. 4 Marks
o In the sheet called “Stride Length”, 3D (x,y,z) coordinates of a marker placed on the left heel (L.Heel) are provided. In this sheet:
i. Calculate length of the left stride.
ii. Note. Description of how the stride length was measured should have already been provided in the Methodology section. 4 Marks
SP2604 Methodology Assignment
o Use sheet called “velocity-acceleration”. In this sheet:
i. Calculate instantaneous velocity and acceleration of the ankle, knee, and hip joints for rotations happened in the sagittal plane. Clearly provide relevant headings to identify different columns which contain your calculations, or use headings already provided;
ii. Note. Description of how the instantaneous velocity and acceleration were calculated should have already been provided in the Methodology section.
iii. Plot Knee velocity. Use appropriate title and units for each axis.
iv. In the result section, report largest velocity of the knee joint observed during the stride and comment whether this maximum velocity was during flexion or extension of the knee joint. Note differences in the sign of velocity during flexion or extension of the knee joint. Report the largest velocity regardless of the sign.10 Marks
SP2604 Methodology Assignment
o Use sheet called “Phase Angle&Angle-Angle”. In this sheet:
i. Calculate “Phase Angles” for the Ankle and Knee joints. DO NOT ADJUST CALCULATED PHASE ANGLES TO EXPRESS THEM FROM A RIGHT ZERO.
ii. Plot “Phase Plots” for the Ankle and Knee joints; Use appropriate title and units for each axis. 8 Marks
iii. Plot “Angle-Angle diagram” for the Ankle-Knee; Use an arrow(s) to identify direction of the unfolding movement (stride). Use appropriate title and units for each axis. 2 Marks
iv. Calculate Continuous Relative Phase (CRP) for Ankle-Knee. DO NOT ADJUST CALCULATED PHASE ANGLES TO EXPRESS THEM FROM A RIGHT ZERO. SIMPLY SUBTRACT PHASE ANGLE CALCULATED FOR THE PROXIMAL JOINT FROM THE PHASE ANGLE CALCULATED FOR THE DISTAL JOINT.
v. As stated before, your Methodology section should include information on how Phase Angles and CRP are calculated. Cite the reference(s) used.
vi. Plot CRP. Provide axes title.
vii. Comment on whether the ankle and knee joints were coordinated in-phase or out-of-phase for the majority of the stride based on CRP values observed. 10 Marks
SP2604 Methodology Assignment
o Use sheet called “MTU Length”. In this sheet:
i. Calculate range of motion of the ankle and knee joints in the sagittal plane for the stride under study. Show your work.
ii. Your Methodology should have a description of how ROM of the ankle and knee were calculated. 2 Marks
iii. Use coefficients of the regression line reported by Grieve et al. (1978) to calculate %change in the Triceps Surae muscle-tendon unit (MTU) length, and minimum and maximum length of the MTU length during the one stride under study (Excel rows 168-331). To this end:
▪ Calculate and report in the Excel file, %alterations in the MTU length due to Ankle joint angles during the stride;
▪ Calculate and report in the Excel file, %alterations in the MTU length due to Knee joint angles during the stride;
▪ Calculate and report in the Excel file, total %alterations in the MTU length due to combined Ankle and Knee joint angles during the stride;
▪ Calculate in the Excel file, and report in the Results section minimum and maximum MTU length during the stride. (Note. Greieve’s coefficients are also included in the Excel sheet)
SP2604 Methodology Assignment
iv. Your Methodology should have a description on how change in the Triceps Surae muscle-tendon unit length was calculated. 10 Marks
v. Calculate and report in the Results section, Tricpes Surae muscle-tendon unit minimum and maximum strain during the one stride under study. Your Methodology should have a description on how strain in the Triceps Surae muscle-tendon unit length was calculated. Calculate both positive and negative strains observed.
vi. Comment on where the shortest and longest lengths of the Triceps Surae muscle-tendon unit were observed during the stride (i.e., during stance or swing phase of the gait). 2 Marks
o Use sheet called “Lat Mal linear displacement”. In this sheet:
i. Calculate linear displacement of the lateral malleolus due to knee rotation during the one stride under study.
ii. Your Methodology should have a description on how linear displacement of the lateral malleolus was calculated.
iii. Report linear displacement of the lateral malleolus during knee rotation in one stride in the Results section. 6 Marks
SP2604 Methodology Assignment
To be continue…