The medial longitudinal arch plays a major role in determining lower extremity kinematics. Thus, it is necessary to understand the dynamics of the arch structure in response to load. The purpose of this study was to examine arch function in high- and low-arched feet during a vertical loading condition. Ten high- and ten low-arched females performed five trials in a sit-to-stand exercise. Ground reaction force (1200 Hz) and three-dimensional kinematics (240 Hz) were collected simultaneously. The high-and low-arched athletes had no differences in vertical deformation of the arch. High-arched participants were less everted than the low-arched athletes; furthermore, the high-arched athletes had smaller mid-forefoot eversion excursions. Differences between the high-arched and low-arched athletes occur through and motion at the mid-forefoot joint.
Douglas W. Powell, Benjamin Long, Clare E. Milner and Songning Zhang
Steven J. Kavros
Plantar fasciitis is a common foot disorder that affects more than two million Americans each year. Conservative management of plantar fasciitis is the first line of treatment by the medical specialist who frequently encounters this common foot complaint. In this study, 50 patients with plantar fasciitis of 4 weeks duration but less than 12 weeks were randomized into two groups. One group of 25 patients used the AirHeel (Aircast, Inc.) and the second group of 25 used the 1st Step prefabricated foot insert (Wrymark, Inc). Standardized weight-bearing radiographs were obtained in order to categorize the foot type: normal arch, pes planus, or pes cavus. Patients were initially evaluated and at 12 weeks they returned for a subsequent visit. The contact area of the foot with the AirHeel and 1st Step insert were similar, an increase of 27% and 26%, respectively, over the contact area barefoot. There was a noted difference in force reduction with the two devices. The AirHeel reduced the midstance force by 20.19%, as compared to the 1st Step insert which showed a 1.03% increase in midstance force. Patients with a higher initial pain score seemed to respond better initially to the AirHeel (p = 0.015) than the 1st Step insert (p = 0.035). This study demonstrates the benefits of offloading the foot at midstance with two devices to relieve the discomfort associated with plantar fasciitis. The Aircast AirHeel is a new modality for dynamic, functional treatment of proximal plantar fasciitis.
Dorsey S. Williams III, Irene S. McClay, Joseph Hamill and Thomas S. Buchanan
High- and low-arched feet have long been thought to function differently. The purpose of this study was to investigate the relationship between arch structure and lower extremity mechanics in runners with extreme pes planus and pes cavus. It was hypothesized that low-arched individuals would exhibit an increased rearfoot eversion excursion, eversion/tibial internal rotation ratio, and increased angular velocity in rearfoot eversion when compared to high-arched runners. In addition, it was hypothesized that high-arched runners would exhibit greater vertical loading rates. Twenty high-arched and 20 low-arched runners with histories of running-related injuries were included in this study. Low-arched runners were found to have increased rearfoot eversion excursion, eversion to tibial internal rotation ratio, and rearfoot eversion velocity. High-arched runners had increased vertical loading rate when compared to low-arched runners. These results suggest that arch structure is associated with specific lower extremity kinematics and kinetics. Differences in these parameters may subsequently lead to differences in injury patterns in high-arched and low-arched runners.
Nancy A. Baker, Kaihua Xiu, Krissy Moehling and Zong-Ming Li
The purpose of this paper is to describe the transverse metacarpal arch (TMA) during a dynamic typing task. Static/relaxed and dynamic typing TMA were collected from 36 right-handed females with musculoskeletal discomfort using a motion capture system. While the angle of right TMA static/relaxed posture (10.1° ± 5.5°) was significantly larger than the left (8.5° ± 5.6°) (P < .05), the right dynamic posture (10.6° ± 4.3°) was not significantly different from the left (10.3° ± 5.5°) (P = .66). Within both these mean scores, there was considerable individual variation, with some subjects demonstrating very flat TMA, and some very curved. The results indicate that TMA angular postures both for static/relaxed and dynamic typing are highly variable both between individuals and between individual hands.
Jaclyn Megan Sions, Elisa Sarah Arch and John Robert Horne
. PubMed doi:10.2147/VHRM.S50588 25075192 2. Klute GK , Berge JS , Orendurff MS , Williams RM , Czerniecki JM . Prosthetic intervention effects on activity of lower-extremity amputees . Arch Phys Med Rehabil . 2006 ; 87 : 717 – 722 . PubMed doi:10.1016/j.apmr.2006.02.007 10.1016/j
Susan L. Snouse, Mark R. Casterline and Bradford Stephens
Column-editor : Marjorie J. Albohm
Jennifer S. Howard and Dustin Briggs
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Elisa S. Arch and Bretta L. Fylstra
The large, late-stance energy generated by the ankle is believed to be critical during gait. However, the distal foot absorbs/dissipates a considerable amount of energy during the same phase. Thus, the energy generated by the combined ankle–foot system is more modest, which raises questions regarding the necessity of such a large ankle power and the interplay between foot and ankle energetics. This study aimed to evaluate our conservation of energy hypothesis, which predicted if distal foot energy absorption/dissipation was reduced, then less energy would be generated at the ankle and thus the same combined ankle–foot energetics would be achieved. Motion analysis data were collected as healthy subjects walked under 2 conditions (Shoes, Footplate). In the Footplate condition, the shoe was replaced with a customized, rigid footplate with a rocker profile. In support of the hypothesis, there was significantly less positive ankle and less negative distal foot work with footplate use, resulting in very similar combined ankle–foot work between conditions. These findings suggest that there is an interplay between the energy generated by the ankle and absorbed by the foot. This interplay should be considered when designing orthotic and prosthetic ankle–foot systems and rehabilitation programs for individuals with weakened ankle muscles.
Elisa S. Arch, Sarah Colón and James G. Richards
Breast and bra motion research aims to understand how the breasts/bra move to aid development of apparel that minimizes motion. Most previously published research has tracked nipple motion to represent bra motion. However, this method does not provide information regarding regional tissue motion. A more comprehensive approach might facilitate understanding how the entire soft-tissue mass moves during physical activities. This study developed and tested an objective method to comprehensively measure 3-dimensional bra motion, including regional displacement and velocity, displacement phasing, and surface stretch. To test the method, 6 females were fitted with a minimally supportive, seamless bra (small bra n = 3; large bra n = 3). Data were collected as participants ran on a treadmill. Results indicated marker displacement, velocity, link stretch, and link stretch velocities reached as high as 52.6 (6.8) mm, 504.8 (88.7) mm/s, 29.5% (7.1%) of minimum length, and 3.8 (1.0) mm/s/mm, respectively, with the large bra having greater motions compared with the small. Most bra motion occurred above/below the nipple region and at the bra’s strap–body interface, independent of bra size. Importantly, maximum marker displacement and velocity did not occur at the nipple. Measurements obtained from this new method may be important for designing innovative clothing that minimizes bra motion during physical activity.
Sarah P. Shultz, Jinsup Song, Andrew P. Kraszewski, Jocelyn F. Hafer, Smita Rao, Sherry Backus, Rajshree M. Hillstrom and Howard J. Hillstrom
with overuse. Planus foot types are often associated with a lower arch structure and have been linked to increased frontal plane motion and subsequently different plantar pressures across the forefoot 7 and midfoot. 8, 9 Additionally, a lower arched foot has been associated with increased risk for