Influence of Dynamic Strength Index on Countermovement Jump Force-, Power-, Velocity-, and Displacement-Time Curves
The dynamic strength index (DSI), often calculated as the ratio of countermovement jump (CMJ) propulsion peak force to isometric mid-thigh pull (IMTP) peak force, is said to inform whether ballistic or maximal strength training is warranted for a given athlete. CMJ propulsion peak force is highly in...
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| Format: | Article |
| Language: | English |
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MDPI AG
2017-09-01
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| Series: | Sports |
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| Online Access: | https://www.mdpi.com/2075-4663/5/4/72 |
| _version_ | 1811280438562390016 |
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| author | John J. McMahon Paul A. Jones Thomas Dos’Santos Paul Comfort |
| author_facet | John J. McMahon Paul A. Jones Thomas Dos’Santos Paul Comfort |
| author_sort | John J. McMahon |
| collection | DOAJ |
| description | The dynamic strength index (DSI), often calculated as the ratio of countermovement jump (CMJ) propulsion peak force to isometric mid-thigh pull (IMTP) peak force, is said to inform whether ballistic or maximal strength training is warranted for a given athlete. CMJ propulsion peak force is highly influenced by jump strategy, however, which is not highlighted by the DSI alone. This study aimed to quantitatively compare CMJ force-, power-, velocity-, and displacement-time curves between athletes who achieved high versus low DSI scores. Fifty-three male collegiate athletes performed three CMJs and IMTPs on a force platform. Athletes were ranked based on DSI score and the CMJ kinetic and kinematic-time curves of the bottom and top twenty athletes were compared. The low DSI group (0.55 ± 0.10 vs. 0.92 ± 0.11) produced greater IMTP peak force (46.7 ± 15.0 vs. 31.1 ± 6.6 N·kg−1) but a larger braking net impulse in the CMJ, leading to greater braking velocity and larger countermovement displacement. This strategy resulted in a similar CMJ propulsion peak force (25.9 ± 2.2 vs. 25.4 ± 3.1 N·kg−1) to the high DSI group. These results, taken together with those of previous studies, support the notion of ballistic versus maximal strength training likely being better suited to low versus high DSI scorers, respectively. |
| first_indexed | 2024-04-13T01:13:45Z |
| format | Article |
| id | doaj.art-ec1e0e72a25e4af8b2d35eb193a48219 |
| institution | Directory Open Access Journal |
| issn | 2075-4663 |
| language | English |
| last_indexed | 2024-04-13T01:13:45Z |
| publishDate | 2017-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sports |
| spelling | doaj.art-ec1e0e72a25e4af8b2d35eb193a482192022-12-22T03:09:01ZengMDPI AGSports2075-46632017-09-01547210.3390/sports5040072sports5040072Influence of Dynamic Strength Index on Countermovement Jump Force-, Power-, Velocity-, and Displacement-Time CurvesJohn J. McMahon0Paul A. Jones1Thomas Dos’Santos2Paul Comfort3Directorate of Sport, Exercise and Physiotherapy, University of Salford, Frederick Road, Salford M6 6PU, UKDirectorate of Sport, Exercise and Physiotherapy, University of Salford, Frederick Road, Salford M6 6PU, UKDirectorate of Sport, Exercise and Physiotherapy, University of Salford, Frederick Road, Salford M6 6PU, UKDirectorate of Sport, Exercise and Physiotherapy, University of Salford, Frederick Road, Salford M6 6PU, UKThe dynamic strength index (DSI), often calculated as the ratio of countermovement jump (CMJ) propulsion peak force to isometric mid-thigh pull (IMTP) peak force, is said to inform whether ballistic or maximal strength training is warranted for a given athlete. CMJ propulsion peak force is highly influenced by jump strategy, however, which is not highlighted by the DSI alone. This study aimed to quantitatively compare CMJ force-, power-, velocity-, and displacement-time curves between athletes who achieved high versus low DSI scores. Fifty-three male collegiate athletes performed three CMJs and IMTPs on a force platform. Athletes were ranked based on DSI score and the CMJ kinetic and kinematic-time curves of the bottom and top twenty athletes were compared. The low DSI group (0.55 ± 0.10 vs. 0.92 ± 0.11) produced greater IMTP peak force (46.7 ± 15.0 vs. 31.1 ± 6.6 N·kg−1) but a larger braking net impulse in the CMJ, leading to greater braking velocity and larger countermovement displacement. This strategy resulted in a similar CMJ propulsion peak force (25.9 ± 2.2 vs. 25.4 ± 3.1 N·kg−1) to the high DSI group. These results, taken together with those of previous studies, support the notion of ballistic versus maximal strength training likely being better suited to low versus high DSI scorers, respectively.https://www.mdpi.com/2075-4663/5/4/72ballistic trainingstrength trainingtemporal phase analysisathlete monitoring |
| spellingShingle | John J. McMahon Paul A. Jones Thomas Dos’Santos Paul Comfort Influence of Dynamic Strength Index on Countermovement Jump Force-, Power-, Velocity-, and Displacement-Time Curves Sports ballistic training strength training temporal phase analysis athlete monitoring |
| title | Influence of Dynamic Strength Index on Countermovement Jump Force-, Power-, Velocity-, and Displacement-Time Curves |
| title_full | Influence of Dynamic Strength Index on Countermovement Jump Force-, Power-, Velocity-, and Displacement-Time Curves |
| title_fullStr | Influence of Dynamic Strength Index on Countermovement Jump Force-, Power-, Velocity-, and Displacement-Time Curves |
| title_full_unstemmed | Influence of Dynamic Strength Index on Countermovement Jump Force-, Power-, Velocity-, and Displacement-Time Curves |
| title_short | Influence of Dynamic Strength Index on Countermovement Jump Force-, Power-, Velocity-, and Displacement-Time Curves |
| title_sort | influence of dynamic strength index on countermovement jump force power velocity and displacement time curves |
| topic | ballistic training strength training temporal phase analysis athlete monitoring |
| url | https://www.mdpi.com/2075-4663/5/4/72 |
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