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  1. Does performing drop jumps with additional eccentric loading improve jump performance?
    Aboodarda SJ, Byrne JM, Samson M, Wilson BD, Mokhtar AH, Behm DG
    J Strength Cond Res, 2014 Aug;28(8):2314-23.
    PMID: 24796986 DOI: 10.1519/JSC.0000000000000498
    Previous investigators have speculated that applying additional external load throughout the eccentric phase of the jumping movement could amplify the stretch-shortening cycle mechanism and modulate jumping performance and jump exercise intensity. The aims of this study, therefore, were to determine the effect of increased eccentric phase loading, as delivered using an elastic device, on drop jumps (DJs) performed from different drop heights. Of specific interest were changes in (a) the kinetics; eccentric and concentric impulse, rate of force development (RFD), concentric velocity and (b) the electromyographic (EMG) activity of leg muscles. In a randomized repeated-measure study, 15 highly resistance trained male subjects performed DJs from 3 heights (20, 35, and 50 cm) under 3 different conditions: body weight only (free DJ) and with elastic bands providing downward force equivalent to 20% (+20% DJ) and 30% (+30% DJ) of body mass. All DJs were recorded using video and force plate data that were synchronized with EMG data. Results demonstrated that using additional tensile load during the airborne and eccentric phases of the DJ could enhance eccentric impulse (p = 0.042) and RFD (p < 0.001) and resulted in small to moderate effect size (ES) increases in quadriceps intergrated EMG across the eccentric phase (0.23 > ES > 0.51). The observed greater eccentric loading, however, did not immediately alter concentric kinetics and jump height nor did it alter muscle activation levels during this phase. The findings indicated that, in addition to the conventional technique of increasing drop height, using a tensile load during the airborne and eccentric phases of the DJ could further improve eccentric loading of DJs. As it has been suggested that eccentric impulse and RFD are indicators of DJ exercise intensity, these findings suggest that the loaded DJs, using additional elastic load, may be an effective technique for improving DJ exercise intensity without acute effects on the jumping performance and neuromuscular activation level in highly trained athletes.
    Matched MeSH terms: Quadriceps Muscle/physiology*
  2. Contralateral Obturator Nerve to Femoral Nerve Transfer for Restoration of Knee Extension After Acute Flaccid Myelitis: A Case Report
    Doi K, Sem SH, Hattori Y, Sakamoto S, Hayashi K, Maruyama A
    JBJS Case Connect, 2019 Dec;9(4):e0073.
    PMID: 31850914 DOI: 10.2106/JBJS.CC.19.00073
    CASE: A 7-year-old boy presented with left femoral and obturator nerves (ONs) palsy after an asthmatic attack with a viral prodrome, and his right lower limb was unaffected. He was diagnosed with acute flaccid myelitis (AFM) after positive spinal magnetic resonance imaging findings. After contralateral ON to femoral nerve transfer (CONFNT), his left quadriceps was reinnervated at 5.5 months, full knee extension was recovered at 14 months, and good functional outcomes were achieved at 31 months.

    CONCLUSIONS: This first clinical report on CONFNT demonstrated a feasible good alternative in treating young patients with AFM with unilateral L2-L4 palsy and short duration of deficit.

    Matched MeSH terms: Quadriceps Muscle/physiology
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