SLR - May 2017 - Jordan P. Deliman
Reference: Strutzenberger G, Alexander N, Bamboschek D, Claas E, Langhof H, Schwameder H. Uphill Walking: Biomechanical Demand on the Lower Extremities of Obese Adolescents. Gait & Posture. 54 (2017):20–26.Scientific Literature Review
Reviewed By: Jordan P. Deliman, DPM
Residency Program: St. Elizabeth’s Medical Center, Brighton, MA
Podiatric Relevance: In the escalating global epidemic of obesity among adolescents, it is inevitable that members of this population will be seen in almost every podiatric practice due to increased risk of overuse injuries. Many of the complaints can be improved by weight loss in tandem with conservative and surgical care. To this point, walking is typically recommended to patients as an appropriate form of exercise as it has low risk for musculoskeletal injury. In the adult population, the metabolic rate can be modulated during walking by increasing speed and/or increasing inclination. Thus, for our adolescent patients who cannot increase their speed due to other pedal complaints, perhaps increasing their inclination could be a more practical alternative for effective exercise. It is important for practitioners to recognize what this article hypothesized. The differences between the obese and normal-weighted populations may be more pronounced with increasing inclination found in uphill walking, which can increase stress on the musculoskeletal system.
Methods: Participants included 11 height- and age-matched obese adolescents (BMI: 31.1 ± 3.5 kg/m2,14.5 ± 1.41 years, five female, six male) and 11 normal-weight adolescents (BMI: 19.0 ± 1.7 kg/m2, 14.3 ± 1.86 years, five female, six male). They walked at 1.11 m/s on a ramp with two force plates at inclinations including 0°, 6° and 12°. Additional kinematic data was collected by standardized marker placement and an eight-camera infrared motion system. Data analysis was processed and applied to statistical analysis comparing spatio-temporal, peaks GRFs, LE joint angles, moments and powers analyzed by two-way ANOVA and T-tests.
Results: There was a significant effect of inclination on almost all variables. The hip joint being the most affected, followed by the knee and ankle joint. The obese participants had an increased stance time/shorter swing phase, increased knee flexion with increased valgus angle and an increased peak hip flexion with increased adduction moment compared to the control group. At the ankle in the sagittal plane, the obese participants were more dorsiflexed at initial contact, with increased significance at the 12° inclination. In the frontal plane, the ankle and knee joints only exhibited group differences at the more extreme 12° inclination.
Conclusions: These results suggest that obese adolescents rely more on the proximal joints during ambulation, and this reliance is more pronounced during uphill walking. The relatively smaller bone mass and decreased ratio of appendicular skeletal muscle to lean tissue of the extremities suggest increased loading of the musculoskeletal system in obese adolescent populations and, when coupled with malalignment pathologies, may increase the risk of overuse injuries, including osteoarthritis, compared to their normal-weighted counterparts.