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Biomedical subjects

W Mack Hardaker

Publications and source records attributed to W Mack Hardaker.

2 recordsLinked to original sources

Forefoot loading during 3 athletic tasks.

BACKGROUND: Due to the popularity of soccer and the high incidence of injury among soccer players, it is valuable to know the effects of tasks like side cuts, crossover cuts, and forward acceleration on the foot. PURPOSE: To determine the differences in forefoot loading during three different athletic tasks. STUDY DESIGN: Descriptive laboratory study. METHODS: Thirty-six subjects (17 women and 19 men) were tested. Subjects ran a slalom-style agility course 5 times while plantar pressure data was collected at 100 Hz. Plantar pressure was recorded under both feet; however, a right-foot contact was used in the analysis of the side-cut task, a left-foot plant was used in the analysis of the crossover cut, and an average of the 3 steps of acceleration were used in the analysis. The peak pressure, contact area, and contact time for the entire foot were compared between the 3 tasks. The force and the force-time integral were obtained during 5 trials for each of the 3 tasks. The foot was divided into 8 masked regions, which were used to determine the loading patterns specifically in the forefoot. Each variable was analyzed using a 1 x 3 analysis of variance to determine differences between the three movement tasks in the forefoot region (a = .05). RESULTS: Significant differences in peak pressure, contact area, and contact time existed between the movement tasks when examining the entire foot. In addition, significant differences in the force-time integral and peak pressure in the forefoot existed between the movement tasks. The force-time integral was highest during the side cut in the medial forefoot, hallux, and the lesser toes, while the force-time integral was highest during the crossover cut in the middle forefoot and the lateral forefoot. Similarly, the peak pressure was highest during the side cut in the medial forefoot, hallux, and the lesser toes, while peak pressure was highest in the middle forefoot during the acceleration task and highest in the lateral forefoot during the crossover-cutting task. CONCLUSIONS: The results of this study demonstrated that the crossover cut places an increased load on the lateral portion of the forefoot, while the side-cut task places an increased load on the medial portion of the forefoot and the acceleration task places increased load on the middle forefoot. CLINICAL RELEVANCE: The differences in loading patterns based on athletic task are important for understanding potential injury mechanisms. In addition, this information could be important for defining a return to play protocol for athletes who have had specific injuries.

Adult↗

The reliability and reproducibility of foot type measurements using a mirrored foot photo box and digital photography compared to caliper measurements.

UNLABELLED: The height of the medial longitudinal arch (MLA) is thought to be a predisposing factor to various lower extremity injuries. Discrepancy exists as to whether MLA height plays a role in injury prevention. The purpose of this study was to determine the intertester and intratester reliability, and the validity of the mirrored foot photo box (MFPB) and caliper measurements to radiographic measurements. METHODS: Thirty subjects with equal numbers of men and women were recruited. Both feet were tested (n=60) in a 90% weight bearing stance. A set of anatomic landmarks were palpated, marked, and measured using a caliper, MFPB, and radiographs. The protocol was completed by two testers on 2 days approximately 1 week apart. Intertester and intratester reliability were determined using the intraclass correlation coefficient (ICC)(2,k) and the ICC(2,1), respectively. Validity of both measurement techniques to radiographic measurements was determined using the ICC(2,k). RESULTS: The intertester reliability ranged from 0.991 to 0.577, while the intratester reliability ranged from 0.994 to 0.527, with first metatarsal angle being the only variable with poor reliability. Most variables demonstrated acceptable validity between the MFPB and the caliper measurements, and acceptable validity between the MFPB and calipers compared to radiographic measurements. The MFPB took 51.3+/-19.6s per foot while the caliper measurements averaged 227.4+/-68.9s to complete the measurements. DISCUSSION: The MFPB is as reliable as the caliper measurements, and offers better intertester reliability. Both the caliper and MFPB measurements demonstrated acceptable validity to radiographic measurements and testing time was reduced when using the MFPB compared to calipers.

Adolescent↗