A century of research has described the development of walking based on periodic gait over a straight, uniform path. The current study provides the first corpus of natural infant locomotion based on spontaneous activity during free play. Locomotor experience was immense: 12- to 19-month-olds averaged 2368 steps and fell 17 times/hour. Novice walkers traveled farther faster than expert crawlers, but fall rates were comparable, suggesting that increased efficiency without increased cost motivates expert crawlers to transition to walking. After walking onset, natural locomotion dramatically improved: Infants took more steps, traveled farther distances, and fell less. Walking was distributed in short bouts with variable paths—frequently too short or irregular to qualify as periodic gait. Nonetheless, measures of periodic gait and natural locomotion were correlated, indicating that better walkers spontaneously walk more and fall less. Immense amounts of time-distributed, variable practice constitute the natural practice regimen for learning to walk.

Introduction: Continuous compression implants (CCI) are a fixation device formed from nitinol, a shape memory alloy. This alloy is durable enough to augment fixation and combined with its small footprint, versatile enough to insert into areas that are too small for K wires or lag screws to hold a provisional fixation. Case Report: We used CCIs to successfully stabilize the transverse segments in three posterior column with posterior wall fractures. Conclusion: CCIs can be used to provisionally reduce posterior column with posterior wall acetabular fractures and stabilize small pelvic bone fragments that may be difficult to hold with lag screws. These cases highlight a novel augmentation of the surgical treatment of posterior column with posterior wall fractures.

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Background:Orthopaedic surgeons are at high risk for experiencing work-related musculoskeletal (MSK) injuries and chronic pain due to repetitive large magnitude forces, altered posture from lead vests, and prolonged irregular body positions. We sought to synthesize available evidence regarding (1) the biomechanics of orthopaedic surgery and (2) MSK injuries sustained by orthopaedic surgeons with subsequent treatment and consequences.Methods:To conduct this systematic review, we queried 4 databases (PubMed, Embase, MEDLINE, and Web of Science) for original research studies presenting on the biomechanics of orthopaedic surgery or MSK injuries sustained by orthopaedic surgeons. Studies were excluded if they were not original research (i.e., reviews) or reported on non-MSK injuries and injuries in patients or nonorthopaedic specialists. The literature search yielded 3,202 publications, 34 of which were included in the final analysis.Results:Eight studies reported on the biomechanics of orthopaedic surgery. Surgeons spent an average 41.6% of operating time slouched. Head and whole spine angles were closest to natural standing position when using a microscope for visualization and with higher surgical field heights. Use of lead aprons resulted in a shifted weight distribution on the forefoot, gain in thoracic kyphosis, and increase in lateral deviation from postural loading. Twenty-six studies reported on MSK symptoms and injuries experienced by orthopaedic surgeons, with an overall prevalence from 44% to 97%. The most common body regions involved were lower back (15.2%-89.5%), hip/thigh (5.0%-86.6%), neck (2.4%-74%), hand/wrist (10.5%-54%), shoulder (7.1%-48.5%), elbow (3.1%-28.3%), knee/lower leg (7.9%-27.4%), and foot/ankle (7%-25.7%). Of surgeons with any reported MSK symptom or injury, 27% to 65.7% required nonoperative treatment, 3.2% to 34.3% surgery, and 4.5% to 31% time off work. Up to 59.3% of surgeons reported that their injuries would negatively influence their ability to perform surgical procedures in the future.Conclusions:The orthopaedic surgeon population experiences a high prevalence of MSK symptoms and injuries, likely secondary to the biomechanical burdens of tasks required of them during strenuous operations.Level of Evidence:Level III. See Instructions for Authors for a complete description of levels of evidence.