geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Range of motion and leg rotation affect electromyography activation levels of the superficial quadriceps muscles during leg extension


, : Range of motion and leg rotation affect electromyography activation levels of the superficial quadriceps muscles during leg extension. Journal of Strength and Conditioning Research 28(9): 2536-2545

Leg extension (LE) is commonly used to strengthen the quadriceps muscles during training and rehabilitation. This study examined the effects of limb position (POS) and range of motion (ROM) on quadriceps electromyography (EMG) during 8 repetitions (REP) of LE. Twenty-four participants performed 8 LE REP at their 8 repetition maximum with lower limbs medially rotated (TI), laterally rotated (TO), and neutral (NEU). Each REP EMG was averaged over the first, middle, and final 0.524 rad ROM. For vastus medialis oblique (VMO), a REP × ROM interaction was detected (p < 0.02). The middle 0.524 rad produced significantly higher EMG than the initial 0.524 rad for REP 6-8 and the final 0.524 rad produced higher EMG than the initial 0.524 rad for REP 1, 2, 3, 4, 6, and 8 (p ≤ 0.05). For rectus femoris (RF), EMG activity increased across REP with TO generating the greatest activity (p < 0.001). For vastus lateralis (VL), EMG increased across REP (p < 0.001) with NEU and TO EMG increasing linearly throughout ROM and TI activity greatest during the middle 0.524 rad. We conclude that to target the VMO, the optimal ROM is the final 1.047 rad regardless of POS, while maximum EMG for the RF is generated using TO regardless of ROM. In contrast, the VL is maximally activated using TI over the first 1.047 rad ROM or in NEU over the final 0.524 rad ROM.

US$19.90

PMID: 25148303

DOI: 10.1519/JSC.0000000000000582


Other references

Borocci, S.; Bronzolino, N.; Giordani, M.; Grandinetti, F., 2010: Cationic noble gas hydrides: a theoretical investigation of dinuclear HNgFNgH+ (Ng = He-Xe). Theoretical calculations at the B3LYP, MP2, and CCSD(T) levels of theory disclose the conceivable existence of cationic noble gas hydrides containing two Ng atoms. These species have a general formula of HNgFNgH(+) (Ng = He-Xe), and are the cation...

Robin, V.; Charton, A.; Morange, R., 1950: Streptomycin in veterinary medicine. In general, infections in the horse, cow, dog and turkey caused by Pseudomonas pyocyanea, Staph. aureus, Pasteurella septica, Bact. coti, Salmonella sp, , Proteus sp. and Haemophilus bronchisepticus responded favourably when appropriately treated...

Khooban, M-Hassan.; Niknam, T.; Blaabjerg, F.; Davari, P.; Dragicevic, T., 2016: A robust adaptive load frequency control for micro-grids. NlmCategory="UNASSIGNED">The goal of this study is to introduce a novel robust load frequency control (LFC) strategy for micro-grid(s) (MG(s)) in islanded mode operation. Admittedly, power generators in MG(s) cannot supply steady elec...

James D.G., 1991: Prospects for integrated management of earth mites in pasture. Ridsdill-Smith, J (Ed ) Proceedings Of A National Workshop on Redlegged Earth Mite, Lucerne Flea And Blue Oat Mite; Meeting, Perth, Western Australia, Australia, September 9-11, Vii+169p Department Of Agriculture: South Perth, Western Australia, Australia Illus Maps Paper 163-165

Yoong, W.; Kolhe, S.; Karoshi, M.; Ullah, M.; Nauta, M., 2006: The obstetric performance of United Kingdom asylum seekers from Somalia: a case-control study and literature review. Little published research exists regarding obstetric performance of immigrant women in the United Kingdom. The aim of this study was to evaluate the obstetric performance and fetal outcomes of Somalian women who received prenatal care and requeste...

Lauterbach, M.D.; Raz, S.; Sander, C.J., 2001: Neonatal hypoxic risk in preterm birth infants: the influence of sex and severity of respiratory distress on cognitive recovery. The authors examined the differential effects of neonatal respiratory distress syndrome (RDS)--a condition associated with elevated risk for neonatal hypoxia-ischemia--on the cognitive development of the two sexes. The authors also attempted to es...

Maestri, A.; Santini, A.; Donati, D.; Gilli, G., 1994: Primary lymphoma of the breast. Clinico-pathologic description of a case. Primary malignant lymphomas of the breast are extremely rare, accounting for only 0.04% to 0.53% of all breast malignancies. Recently a connection between some primary breast lymphomas and mucosa-associated lymphoid tissue (MALT) has been reported...

Faleiro, T.Batista.; Schulz, R.da.Silva.; Jambeiro, J.Eduardo.de.Schoucair.; Tavares, A.; Delmonte, F.Moreira.; Daltro, Gásio.de.Cerqueira., 2016: Viscosupplementation In Ankle Osteoarthritis: A Systematic Review. To evaluate the efficacy of viscosupplementation in patients with osteoarthritis of the ankle. A systematic review to evaluate the evidence in the literature on the use of viscosupplementation for osteoarthritis of the ankle. For this review, we c...

Blair, C.D.; Olson, K.E., 2015: The role of RNA interference (RNAi) in arbovirus-vector interactions. RNA interference (RNAi) was shown over 18 years ago to be a mechanism by which arbovirus replication and transmission could be controlled in arthropod vectors. During the intervening period, research on RNAi has defined many of the components and...

Anagnostopoulos T., 1979: The proximal tubule of necturus is a tight epithelium. Upsala Journal Of Medical Sciences Supplement: