A musculoskeletal multifactorial individualised programme for hamstring muscle injury risk reduction in professional football: results of a prospective cohort study

Abstract

Objective: To test whether a musculoskeletal multifactorial and individualised hamstring muscle injury (HMI) risk reduction programme could reduce HMI risk in professional football.

Methods: We conducted a prospective cohort study in Finnish premier football league teams, with the 2019 season used as a control and an intervention conducted in the 2021 season. Screening was conducted to provide individualised programmes and monitor progress. Cox regression with hazard ratio (HR) was used with HMI as outcome and season as explanatory variable, including all players for primary analysis and those who performed the two seasons for secondary analysis.

Results: 90 players were included in the control and 87 in the intervention seasons; 31 players performed in the 2 seasons. Twenty HMIs were recorded during the control and 16 during the intervention seasons. Cox regression analyses revealed that HMI risk at any given time was not significantly different between control and intervention seasons (for all players: HR 0.77 (95% CI 0.39 to 1.51), p=0.444; for the 31 players: HR 0.32 (95% CI 0.01 to 1.29), p=0.110)). For the 31 players, the HMI burden was significantly reduced in the intervention compared with the control season (RR 0.67 (95% CI 0.53 to 0.85)). Higher compliance with knee strength training, maximal velocity exposure and lower performance reductions in maximal theoretical horizontal force and knee flexor force were associated with lower HMI incidence.

Conclusions: Although the primary analysis did not reveal any significant effect of the intervention to reduce HMI risk in professional football, the programme was feasible, and additional secondary analyses showed a significant association between the intervention and lower HMI burden, incidence and risk.

Keywords: Football; Hamstring; Injury; Prevention.

Figure 1

Intervention screening and training structure of the musculoskeletal multifactorial individualised programme for hamstring muscle injury risk reduction in professional football. The individualised approach included four training categories. The screening result within each category determined each player’s training structure. For example, if a player within a specific team was under the 33% percentile in the lumbopelvic control test, his target training volume for lumbopelvic control was four times per week instead of two (see the last column for training outcome). This was also assuming there was only one game. In two game weeks, volume was dropped by 50%. Training for all players was not individualised, and thus, the same training volume was targeted for all players. More info can be found in Lahti et al. ASLR, active straight leg raise; ROM, range of motion.

Figure 2

Flow chart of the population selection.

Figure 3

Timeline of hamstring injuries during the 2019 and 2021 seasons (including preseason and in-season). (A) All HMI from both seasons relative to season length, including reinjuries. (B) Index HMI from both seasons concerning football exposure used in the Cox regression analysis. The 2019 injuries are visualised as triangles and the 2021 season as circles. The grey shapes are index injuries, and the red represents reinjuries. HMI, hamstring muscle injury.

Figure 4

Relative compliance was reported as the total for each intervention category of the five teams separately during the intervention season. The total compliance % is reported first to the left. The intervention categories are divided into non-individualised (max velocity, postsport ROM, triceps surae and manual therapy) and individualised clusters (lumbopelvic control, ROM, posterior chain strength and sprint mechanical output). The number of index injuries reported per team is on the bottom legend. HMI, hamstring muscle injury; ROM, range of motion.