Landing Styles Influences Reactive Strength Index without Increasing Risk for Injury

Sports Medicine International Open

Ahmad Alanazi^2¹  Dana Guy-Cherry^1²  Lauren Miller^1³ 

[1] Majmaah University, Physical Therapy, Al Majma’ah, Saudi Arabia^2;Texas Woman’s University, School of Physical Therapy, Houston, United States^1;UT Health San Antonio, Department of Physical Therapy, San Antonio, United States^3

关键词: landing;    knee;    valgus;    jumping;    drop jump;   

DOI  :  10.1055/a-0608-4280

学科分类：运动医学

来源: Georg Thieme Verlag

【 摘 要 】

The aim was to determine which three landing styles – stiff (ST), self-selected (SS), or soft (SF) – exhibit safer landing mechanics and greater jumping performance. Thirty participants (age: 26.5±5.1 years; height: 171.0±8.8 cm; weight: 69.7±10.1 kg) performed five trials of three randomized drop jump (40 cm) landing styles including SF (~60° knee flexion), ST (knees as straight as possible), and SS. Knee flexion and valgus angles and kinetics were measured. An electromyography system measured muscle activity of the gluteus maximus, quadriceps, hamstrings, tibialis anterior, and gastrocnemius. Reactive strength index (RSI) was used to measure jumping performance. ANOVAs were used to compare the three landings. All landings differed in knee flexion (p2): 0.9) but not valgus (p=.13; η²:.15). RSI (mm·ms^-1) showed differences for all jumps (p2: 0.7) with SS (0.96) showing the highest value, then ST (0.93), and SF (0.64). Ground reaction forces were different between jumps (p2: 0.4) with SF (1.34/bodyweight (bw)) showing lower forces, then SS (1.50/bw), and ST (1.81/bw). No between-jump differences were observed for EMG (p>0.66; η²: 0.3). No landing demonstrated valgus landing mechanics. The SS landing exhibited the highest RSI. However, the 1.8/bw exhibited by the ST landing might contribute to overload of musculotendinous structures at the knee.

【 授权许可】

CC BY-NC-ND