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Context: Inversion ankle sprains can lead to a chronic condition called functional ankle instability (FAI). Limited research has been reported regarding isokinetic measures for the plantar flexors and dorsiflexors of the ankle.Objective: To examine the isokinetic eccentric torque measures of the ankle musculature in participants with stable ankles and participants with functionally unstable ankles during inversion, eversion, plantar flexion, and dorsiflexion.Design: Case-control study. Setting: Athletic training research laboratory. Patients or Other Participants: Twenty participants with a history of ''giving way'' were included in the FAI group. Inclusion criteria for the FAI group included a history of at least 1 ankle sprain and repeated episodes of giving way. Twenty participants with no prior history of ankle injury were included in the control group.Intervention(s): Isokinetic eccentric torque was assessed in each participant.Main Outcome Measure(s): Isokinetic eccentric testing was conducted for inversion-eversion and plantar-flexion-dorsiflexion movements. Peak torque values were standardized to each participant's body weight. The average of the 3 trials for each direction was used for statistical analysis.Results: A significant side-by-group interaction was noted for eccentric plantar flexion torque (P Ͻ .01). Follow-up t tests revealed a significant difference between the FAI limb in the FAI group and the matched limb in the control group. Additionally, a significant difference was seen between the sides of the control group (P ϭ .03). No significant interactions were identified for eccentric inversion, eversion, or dorsiflexion torques (P Ͼ .05).Conclusions: A deficit in plantar flexion torque was identified in the functionally unstable ankles. No deficits were identified for inversion, eversion, or dorsiflexion torque. Therefore, eccentric plantar flexion strength may be an important contributing factor to functional ankle instability.Key Words: isokinetic dynamometer, strength, inversion, eversion, dorsiflexion Key Points• A deficit in plantar-flexion torque was identified in the participants with functionally unstable ankles.• No deficits were noted for inversion, eversion, or dorsiflexion torque.• Eccentric plantar-flexion strength may be an important contributing factor to functional ankle instability.

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In additive manufacturing (AM), melt pool dimension control is needed to accurately build a geometry and determine process precision. Microstructure control is needed for its effect on mechanical properties. This research addresses both for Ti-6Al-4V thin walled structures fabricated by wire feed electron beam AM. Model results show that beam power and beam velocity combinations yielding constant melt pool cross-sectional areas also yield constant solidification cooling rates. Experimental measurements back up this finding and show roughly 20 beta grains across the width of a thin wall deposit which is consistent with an earlier study of single bead deposits, suggesting that links between melt pool geometry and beta grain size are independent of deposition geometry, with significant implications for AM process control.

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The Additive Manufacturing Benchmark Test Series (AM-Bench) was established to provide rigorous measurement test data for validating additive manufacturing (AM) simulations for a broad range of AM technologies and material systems. AM-Bench includes extensive in situ and ex situ measurements, simulation challenges for the AM modeling community, and a corresponding conference series. In 2018, the first round of AM-Bench measurements and the first AM-Bench conference were completed, focusing primarily upon laser powder bed fusion (LPBF) processing of metals, and both LPBF and material extrusion processing of polymers. In all, 46 blind modeling simulations were submitted by the international AM community for comparison with the in situ and ex situ measurements. Analysis of these submissions provides valuable insight into existing AM modeling capabilities. The AM-Bench data are permanently archived and freely accessible online.

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