Abstract
Movement on declined slopes poses unique mechanical stresses when compared to level surfaces. Both downhill (DH) running and walking have seen large amounts of load force absorption on the knee (French 2018; Abe et.al., 2011) with some forces possibly being distributed to the hip and ankle joints. Though research is limited about lower extremity joint kinematics across all three joints. PURPOSE: To better understand the joint forces placed on the hip, knee, and ankle with variable speed and decline gradient METHODS: Nine participants (5 male and 4 female; Age = 24.09 ± 2.81 yrs; Weight = 75.12 ± 13.67 kg; Height = 1724.89 ± 68.58 mm) were asked to walk and run, in five-minute intervals on an instrumented treadmill (Bertec, Inc. Columbus, OH) at self-selected velocities. Conditions were determined in randomized order (C1 = walk flat, C2 = run flat, C3 = DH Walk, C4 = DH Run) and intervals were performed at a flat plane as well as a decline of -9°. Data collection used 8 video cameras recording at 50 hZ. (Theia, Inc., Kingston, Ontario, Canada) and analyzed using Visual 3D (C-Motion, Inc.,Germantown, MD). Data was further analyzed (using C2 vs C4 and C1 vs C3) using a repeated measure ANOVA with Tukey-b post-hoc test (family-wise α = 0.05). RESULTS: Analysis saw significant (p < 0.05) joint forces across all conditions. Highest hip and ankle forces reported in C2 (hip = -20.99±2.06 N/kg; ankle = -20.20±1.86 N/kg). Highest knee forces reported in C4 (knee = -22.07±3.0 N/kg). Highest velocity reported in C2 (2.56±0.44 m/s). CONCLUSION: The current study found C2 imposed higher forces on the ankle and hip compared to other conditions. C4 presented higher forces in the knee. Participants could self-select speeds for each condition, resulting in C2 having the fastest running speed. Evidence has suggested that higher speeds tend to increase joint forces (Schache et al., 2011) which may contribute to the findings of the current study, however, may have significance in a real-world setting. Higher speeds and joint force loading can be an indicator of lower extremity injury (French, 2018). Therefore, future research should look into DH/Flat Running and its implications on injury in an applied setting.
Recommended Citation
Hernandez, Ulises; Pace, Ezrie; Loader, Kaeley; Ramirez, Nathan; Nielsen, Megan; and Bohne, Michael
(2024)
"Downhill Dilemma: Analyzing Joint Force on Variable Speed and Gradient,"
International Journal of Exercise Science: Conference Proceedings: Vol. 14:
Iss.
4, Article 45.
Available at:
https://digitalcommons.wku.edu/ijesab/vol14/iss4/45
Included in
Health and Physical Education Commons, Medical Education Commons, Sports Sciences Commons