Normative isometric plantarflexion strength values for professional level, male rugby union athletes

P077 Upskilling rheumatology therapists in work rehabilitation: an evaluation of the Workwell training programme

“…As mentioned earlier, calf muscle injuries are also common in professional football [2], with widely variable return-to-sport times [1,3]. The mean KIPFT peak force range, from 1.93 to 2.05 xBW, is similar to the SIPFT normative values reported by Lee et al [12], as attained by professional rugby union players. Knowing what the typical isometric peak force scores in these tests are for healthy, injury-free players is an important step in informing sports injury practitioners of the realistic benchmarks to which calf/ankle injured athletes can aspire.…”

“…of dorsiflexion attained by the players in this study is likely much below their maximal individual dorsiflexion angles; therefore, they may not have been in the most favorable position to produce maximal plantar flexor force, despite the findings of Sale et al [23]. However, the limitation of placing each player in their peak dorsiflexion position is that if their ankle mobility changes over time, then so will the ankle angle at which they perform the KIPFT, which may make interpreting peak force changes more difficult, should the approach of Lee et al [12] be taken. Thus, research into the influence of the ankle and knee angles on both the KIPFT and SIPFT (unilateral version) peak force values would be valuable, in addition to comparing the agreement between the peak force values obtained from these tests to determine whether can they be used interchangeably or compared within reasonable limits.…”

“…Although this preliminary study shows that the KIPFT produced good-excellent reliability for peak force and can be conducted in professional football environments in a relatively time-efficient manner, it is worth remembering that we did not measure joint angles (knee and ankle) directly in this study. The authors of a recent study involving professional rugby union players being tested via the SIPFT (unilateral version) placed their participants in maximal dorsiflexion [12]. The peak dorsiflexion angle in professional youth soccer players was reported to be 36.1 ± 4.8 deg., but the values for the individual players ranged from 26.1 to 45.9 deg.…”

“…Half of surveyed strength and conditioning coaches working in football use force plates to regularly assess the force-generating capabilities of their athletes [10]. Force plates have only been used to assess isometric plantar flexion force in studies published since 2022 [11][12][13][14][15][16][17][18][19][20]. Only one study involved football players and included the seated isometric plantar flexor test (SIPFT) to determine its reliability of quantifying peak force [20].…”

“…Despite the abovementioned limitations of the SIPFT protocol utilized by Rhodes et al [20], several other researchers have adopted a similar approach to assessing the isometric peak force capabilities of the plantar flexors [11,[13][14][15][16][17]19]. An alternative approach to conducting the SIPFT, whereby a novel device specifically designed to assess the isometric force capabilities of the plantar flexors was validated [18] and used to assess a large cohort of rugby players, was recently published, thus providing normative reference values [12]. The strengths of the custom device and setup included the removal of a soft foam pad by using ratchet straps to fix the leg in position, thus removing the pad compression issue, and the test was conducted unilaterally, thus overcoming the bilateral strength deficit issue [21].…”