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Muscle injuries are one of the most common traumas occurring in sports. Despite their clinical importance, few clinical studies exist on the treatment of these traumas. Thus, the current treatment principles of muscle injuries have either been derived from experimental studies or been tested only empirically. Although nonoperative treatment results in good functional outcomes in the majority of athletes with muscle injuries, the consequences of failed treatment can be very dramatic, possibly postponing an athlete's return to sports for weeks or even months. Moreover, the recognition of some basic principles of skeletal muscle regeneration and healing processes can considerably help in both avoiding the imminent dangers and accelerating the return to competition. Accordingly, in this review, the authors have summarized the prevailing understanding on the biology of muscle regeneration. Furthermore, they have reviewed the existing data on the different treatment modalities (such as medication, therapeutic ultrasound, physical therapy) thought to influence the healing of injured skeletal muscle. In the end, they extend these findings to clinical practice in an attempt to propose an evidence-based approach for the diagnosis and optimal treatment of skeletal muscle injuries.

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Caution may be warranted in employing aggressive rehabilitation after reconstruction with these devices. Preconditioning of the graft-implant complex before fixation is important.

Recent animal studies have given evidence that vibration loading may be an efficient and safe way to improve mass and mechanical competence of bone, thus providing great potential for preventing and treating osteoporosis. Randomized controlled trials on the safety and efficacy of the vibration on human skeleton are, however, lacking. This randomized controlled intervention trial was designed to assess the effects of an 8-month whole body vibration intervention on bone, muscular performance, and body balance in young and healthy adults. Fifty-six volunteers (21 men and 35 women; age, 19 -38 years) were randomly assigned to the vibration group or control group. The vibration intervention consisted of an 8-month whole body vibration (4 min/day, 3-5 times per week). During the 4-minute vibration program, the platform oscillated in an ascending order from 25 to 45 Hz, corresponding to estimated maximum vertical accelerations from 2g to 8g. Mass, structure, and estimated strength of bone at the distal tibia and tibial shaft were assessed by peripheral quantitative computed tomography (pQCT) at baseline and at 8 months. Bone mineral content was measured at the lumbar spine, femoral neck, trochanter, calcaneus, and distal radius using DXA at baseline and after the 8-month intervention. Serum markers of bone turnover were determined at baseline and 3, 6, and 8 months. Five performance tests (vertical jump, isometric extension strength of the lower extremities, grip strength, shuttle run, and postural sway) were performed at baseline and after the 8-month intervention. The 8-month vibration intervention succeeded well and was safe to perform but had no effect on mass, structure, or estimated strength of bone at any skeletal site. Serum markers of bone turnover did not change during the vibration intervention. However, at 8 months, a 7.8% net benefit in the vertical jump height was observed in the vibration group (95% CI, 2.8 -13.1%; p ‫؍‬ 0.003). On the other performance and balance tests, the vibration intervention had no effect. In conclusion, the studied whole body vibration program had no effect on bones of young, healthy adults, but instead, increased vertical jump height.

Fractures are a rapidly growing problem among older people. Hip fractures alone cost over $20bn (£10bn; €13bn) in the United States in 1997. 1 Any intervention that may reduce the risk of fracture at either the individual or population level therefore warrants critical appraisal. The mainstay of current strategies to prevent fractures is to screen for osteoporosis by bone densitometry and then treat people with low bone density with antiresorptive or other bone-specific drugs. 2-4 However, the strongest single risk factor for fracture is falling and not osteoporosis. 5 6 Despite this fact, few general practitioners will have assessed the risk of falling among their elderly patients or even know how to do it. 7 Risk of falling is also completely overlooked in many important publications on preventing fractures. 4 We argue that a change of approach is needed. Predictive value of bone density measurements Bone densitometry does not give reliable estimates of a person�s true bone mineral density. The planar scan-person�s true bone mineral density. The planar scan-bone mineral density. The planar scan-he planar scanning principle of dual energy x ray absorptiometry, and assumptions in processing the scan data, can underesti-can underestimate or overestimate bone mineral density by 20-50%. 8 This means that a patient with a bone mineral density T a patient with a bone mineral density T score of −1.5 may have a true value between −3.0 and 0 −that is, a range from clear osteoporosis to normal. Thus, not surprisingly, bone mineral density is a poor is a poor predictor of fracture in individuals (fig 1). �n addition, (fig 1). �n addition, �n addition, when different scanners are used on the same patients, the proportion of patients diagnosed with osteoporosis varies from 6% up to 15%. 9 Over 80% of low trauma fractures occur in peo-80% of low trauma fractures occur in people who do not have osteoporosis (defined as T score ≤−2.5). 11 Even if a T score of −1.5 is used to define osteoporosis, 75% of fractures would still occur in peo-Preventing fractures in older people is important. But Teppo Järvinen and colleagues believe that we should be putting our efforts into stopping falls not treating low bone mineral density

Some caution may be warranted when using the implants that showed increased residual displacement, especially if aggressive rehabilitation is to be used. Preconditioning of the hamstring tendon graft-implant complex before tibial fixation is needed.

ABSTRACT:According to experimental studies, low-amplitude high-frequency vibration is anabolic to bone tissue, whereas in clinical trials, the bone effects have varied. Given the potential of whole body vibration in bone training, this study aimed at exploring the transmission of vertical sinusoidal vibration to the human body over a wide range of applicable amplitudes (from 0.05 to 3 mm) and frequencies (from 10 to 90 Hz). Vibration-induced accelerations were assessed with skin-mounted triaxial accelerometers at the ankle, knee, hip, and lumbar spine in four males standing on a high-performance vibration platform. Peak vertical accelerations of the platform covered a range from 0.04 to 19 in units of G (Earth's gravitational constant). Substantial amplification of peak acceleration could occur between 10 and 40 Hz for the ankle, 10 and 25 Hz for the knee, 10 and 20 Hz for the hip, and at 10 Hz for the spine. Beyond these frequencies, the transmitted vibration power declined to 1/10th−1/1000th of the power delivered by the platform. Transmission of vibration to the body is a complicated phenomenon because of nonlinearities in the human musculoskeletal system. These results may assist in estimating how the transmission of vibration-induced accelerations to body segments is modified by amplitude and frequency and how well the sinusoidal waveform is maintained. Although the attenuation of vertical vibration at higher frequencies is fortunate from the aspect of safety, amplitudes >0.5 mm may result in greater peak accelerations than imposed at the platform and thus pose a potential hazard for the fragile musculoskeletal system.