PurposeTo compare acute ACL reconstruction (ACLR) within 8 days of injury with delayed reconstruction after normalized range of motion (ROM), 6–10 weeks after injury. It was hypothesized that acute ACL reconstruction with modern techniques is safe and can be beneficial in terms of patient-reported outcomes and range of motion.MethodsSample size calculation indicated 64 patients would be required to find a 5° difference in ROM at 3 months. Seventy patients with high recreational activity level, Tegner level 6 or more, were randomized to acute (within 8 days) or delayed (6–10 weeks) ACLR between 2006 and 2013. During the first 3 months following surgery patients were contacted weekly by SMS and asked ‘How is your knee functioning?’, with answers given on a Visual-Analog Scale (0–10). ROM was assessed after 3 months by the rehab physiotherapist. Patient-reported outcomes, objective IKDC and manual stability measurements were collected by an independent physiotherapist not involved in the rehab at the 6-month follow-up.ResultsAt 3-month follow-up, 91% of the patients were assessed with no significant differences in flexion, extension or total ROM demonstrated between groups. At the 6-month follow-up, the acute group had significantly less muscle atrophy of the thigh muscle compared to the contralateral leg. Furthermore, a significantly higher proportion of patients in the acute group passed or were close to passing the one leg hop test (47 versus 21%, p = 0.009). No difference was found between the groups in the other clinical assessments. Additionally, no significant difference between the groups was found in terms of associated injuries.ConclusionAcute ACLR within 8 days of injury does not appear to adversely affect ROM or result in increased stiffness in the knee joint when compared to delayed surgery.Level of evidenceII.

Amplitude and timing of electromyographic activity during sprinting. Scand J Med Sci Sports 1996: 6: 15-21. 0 Munksgaard, 1996 The aim of this study was to make descriptive analyses of the muscle activities in the lower extremity during maximal sprinting. Nine healthy sprinters were examined during maximal sprinting using telemetric electromyography (EMG). Seven muscles of the lower extremities were investigated: biceps femoris, medial hamstrings (semimembranosus and semitendinosus), rectus femoris, gluteus maximus, tibialis anterior, lateral gastrocnemius and medial gastrocnemius. The recorded EMG levels during running were expressed as percentage of maximum voluntary isometric contractions ('%omax EMG). For each muscle, the normalized EMG was plotted during the whole running stride cycle and is presented for each muscle. The reason for using this method is to show that it is possible to compare different muscle activities in a runner as well as to make comparisons between runners. Lateral and medial hamstrings and gluteus maximus showed similar activities with peak levels of EMG during footstrike. Rectus femoris had a two-peak activity, with one peak at the middle of the stance phase and the other during the swing phase. The tibialis anterior also showed a two-peak activity, but with the peaks at the beginning of the swing phase and just before foot-strike. The highest activities of the medial and lateral gastrocnemius occurred just before toe-off.The activation of different muscles in the lower extremities in sprinting as shown in recordings of temporal distribution of raw electromyographic (EMG) activity has been studied by several researchers. Maim et al. made a comparative study of the lower extremity in jogging, running and sprinting. The EMG activity was not graded, it only registered activity or not during different parts of the stride cycle (1). In another study Mann and Hagy concluded that increased speed was followed by increased E M G activity in a temporal aspect; however, the activity was not graded (2). Simonsen et al. (3) studied the temporal distribution of EMG from 9 muscles during sprinting together with mechanical analyses. Movement artifacts made it difficult to grade the EMG activity in this study. Mero & Komi used a telemetric device to record activity of elite sprinters during maximal sprinting. The EMG was normalized to maximal integrated EMG during the running stride cycle and the activity was measured ten times during one stride cycle (4). Jacobs et al. (5) studied the activity of the lower legs by integrated EMG in 7 elite runners by telemetric transmission. The recorded EMG levels during running were expressed as a percentage of maximum voluntary isometric contractions. However, the running speed was only 6 m/s. Jacobs et al. (6) also used EMG normalized to maximum isometric contractions in the lower extremities to study the activity in a sprint push-off. This is at the very beginning in the sprint run at the acceleration phase.In comparing fatigued and nonfatigued sprinting, Nummela...

In Sweden, the indirect costs for chronic LBP appear to be substantially higher than the direct costs for pharmaceuticals, medical visits, physiotherapy, andhospitalizations. The high indirect costs indicate that more effective treatments for chronic LBP could potentially lead to cost savings even if the therapy costs were higher.

Eleven sprinters with recent hamstring injuries were compared with nine uninjured runners. The flexibility of the hamstrings and the eccentric and concentric muscle torque were measured in the hamstrings and quadriceps muscles at different angular velocities. Sprinters with a previous hamstring injury had significantly tighter hamstrings than uninjured sprinters had. The uninjured sprinters had significantly higher eccentric hamstring torques at all angular velocities. They also had significantly higher concentric quadriceps and hamstring torques at 30 deg/sec but not at higher velocities. Sprinters with a history of hamstring injury thus differed from uninjured runners, being weaker in eccentric contractions and in concentric contractions at low velocities.

A few studies have shown that eccentric exercise is effective for prevention and treatment of muscle injuries. Most earlier studies on eccentric exercises have used training with advanced equipment. Forward lunges are considered eccentric exercises, and they may be performed without any equipment. These exercises are commonly used by sprint runners. We performed a prospective, randomized, 6-week training study comparing the effects of walking or jumping forward lunges on hamstring and quadriceps strength and function. Thirty-two soccer players were included in the study. The forward lunge training was done as an addition to ordinary soccer training twice a week for 6 weeks. The outcome was measured by the maximal hamstring and quadriceps strength tests and by functional tests with 1-leg hop tests and 30-m sprint runs. Overall muscle pain was evaluated using a visual analogue scale score, and local pain was estimated with an algometer. Whereas the walking lunge improved hamstring strength, the jumping lunge resulted in sprint running improvements. Algometer testing showed a general increase in the pain detection thresholds of all subjects, including the controls. Thus, precautions should be taken when algometers are used for temporal studies of pain. Walking and jumping forward lunges can be used for improving hamstring strength and running speed in young soccer player. The findings may have relevance when designing protocols for prevention and rehabilitation of muscle injuries.