Magnetic resonance imaging： a valuable method for diagnosing chronic lumbago caused by lumbar muscle strain and monitoring healingprocess

Background Magnetic resonance imaging （MRI） is the most sensitive technique for evaluating the healing process and should be performed before the patients return to their exercise routines. The aim of this research was to diagnose chronic lumbago associated with lumbar muscle strain and to monitor healing process by MRI. Methods Sixty-five symptomatic cases of chronic lumbago caused by lumbar muscle strain were collected from March 2009 to October 2011. MRI was used to examine, diagnose and monitor the healing process. The control group included 65 random cases of asymptomatic volunteers. MRI methods included routine sequences of GRE TlWl, TSE T2WI and special sequences of T2-STIR-FS, combined with DWI. We compared the MRI characteristics of symptomatic cases before and after healing and with asymptomatic controls. Results The important MRI characteristics of chronic lumbago with lumbar muscle strain included： （1） The low back muscle showed edema. （2） The low back intermuscular spaces showed edema and/or fluid. （3） The low back spaces beside the spinous process showed edema and/or fluid. （4） The low back vertebral articular process fossae or transverse process fossae showed fluid. Of these image characteristics, the intermuscular space edema provided the best diagnostic sensitivity, Se=83%, with Y1=0.63, Tr=74%. The low back muscle edema provided the best diagnostic specificity, Sp=100%, with Y1=0.66, Tr=83%. And the spaces edema beside the spinous process provided the best diangnostic accuracy, Tr=86%, with YI = 0.71, Se=80%, Sp=91%. The diagnosis accurate could be improved by combining multiple MRI characteristics. The diagnostic accuracy could achieve n=93%, with Y1=0.86, Se=100% and Sp=86% when two characteristics were combined. After rehabilitation care, the edema disappeared on the repeated MRI. Conclusions MRI may well be a useful diagnostic method for lumbago with lumbar muscle strain. Combining routine sequences with T2-STIR-FS and DWI sequences could demonstrate the pathological changes of lumbar muscle strain and monitor the healing.

Spraino:A novel low-friction device for prevention of lateral ankle sprain injuries in indoor sports

A heightened risk for lateral ankle sprain injuries has been associated with excessive shoe-surface friction.‘Spraino’is a novel product specifically designed towards preventing friction-related lateral ankle sprains.In a recent 510-athlete randomized controlled trial,allocation to this“low-friction”shoe-patch resulted in a 53%reduction of severe ankle sprain injuries.Until now,however,a theoretical explanation linking shoe-surface friction and lateral ankle sprain injury mechanism is missing,and the extent to which Spraino reduces shoesurface friction remains unknown.Therefore,the purpose of this study was to present a theoretical link between lateral edge shoe-surface friction and the mechanism of lateral ankle sprain injuries,and ultimately establish the ability of Spraino to reduce lateral edge shoe-surface friction.In this paper,we present a theory on how ankle sprain mechanics are directly affected by the friction between shoe and surface,and why friction modifications might be a viable preventive strategy.When testing slip resistance in a modified mechanical testsetup,we detected a 63%reduction(0.83–0.31)in friction coefficient between the lateral edge of the outsole and the indoor sports floor when adding Spraino to the side of the shoe.Justified in our theory,and the previously established clinical effectiveness,this reduction in friction can mitigate both the risk and severity of lateral ankle sprain injuries.This suggests that reducing friction on the lateral edge of footwear can be an effective ankle sprain injury prevention strategy.