Acute hamstring injuries in Swedish elite football: a prospective randomised controlled clinical trial comparing two rehabilitation protocols

ABSTRACT Background Hamstring injury is the single most common injury in European professional football and, therefore, time to return and secondary prevention are of particular concern. Objective To compare the effectiveness of two rehabilitation protocols after acute hamstring injury in Swedish elite football players by evaluating time needed to return to full participation in football team-training and availability for match selection. Study design Prospective randomised comparison of two rehabilitation protocols. Methods Seventy-five football players with an acute hamstring injury, verified by MRI, were randomly assigned to one of two rehabilitation protocols. Thirtyseven players were assigned to a protocol emphasising lengthening exercises, L-protocol and 38 players to a protocol consisting of conventional exercises, C-protocol. The outcome measure was the number of days to return to full-team training and availability for match selection. Reinjuries were registered during a period of 12 months after return. Results Time to return was significantly shorter for the players in the L-protocol, mean 28 days (1SD±15, range 8-58 days), compared with the C-protocol, mean 51 days (1SD±21, range 12-94 days). Irrespective of protocol, stretching-type of hamstring injury took significantly longer time to return than sprinting-type, L-protocol: mean 43 vs 23 days and C-protocol: mean 74 vs 41 days, respectively. The L-protocol was significantly more effective than the C-protocol in both injury types. One reinjury was registered, in the C-protocol. Conclusions A rehabilitation protocol emphasising lengthening type of exercises is more effective than a protocol containing conventional exercises in promoting time to return in Swedish elite football

Issues in Capturing and Utilizing Non-Functional Requirements along the Road to Servitization

The design process aims to maximize the value in the end solution. For traditional manufacturing firms pursuing a servitization strategy, non-functional requirements become more important compared to before. Therefore, this paper investigates issues in capturing and utilizing non-functional requirements for value creation in a servitizing firm. A single case study was conducted, which resulted in six issues across the design process. It was evident from the research that the firm requires new support to enable a better inclusion of non-functional requirements in the design process.open access</p

Optimising Hamstring Strength and Function for Performance After Hamstring Injury

Hamstring strain injury often results in neuromuscular performance deficits that persist beyond rehabilitation and the return to full training and competitive sport. It seems appropriate to address these deficits as a part of a sport-specific training program which primarily aims to enhance performance. Prolonged deficits in horizontal ground reaction forces in sprinting, repeat sprint performance, knee flexor eccentric strength and biceps femoris long head fascicle lengths have been observed in multiple studies of hamstring strain injury. Why such deficits persist beyond the return to sport is not known, although persistent neuromuscular inhibition of the injured muscles has been proposed. There is limited and mixed evidence for sprint running kinematic (technique) differences between previously injured and uninjured limbs or athletes, although more work in this area seems warranted. While there is some uncertainty about the optimal mix of methods for addressing the aforementioned deficits, sport-specific running programs in conjunction with continued monitoring of acceleration phase sprint performance and repeated sprint ability seem appropriate. Heavy strength training with at least some eccentrically biased exercises is also recommended to address deficits in eccentric strength and muscle fascicle lengths