Ground reaction force bilateral asymmetries during submaximal sagittal plane lifting from the floor

Maines, Joseph M.; Reiser, Raoul F.

doi:10.1016/j.ergon.2005.08.004

Cited by 17 publications

(11 citation statements)

References 25 publications

(34 reference statements)

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“…As expected, even in this healthy population, functional asymmetries were typically present, which is similar to Maines & Reiser (2006) who found asymmetries in the GRFv of subjects during a submaximal lifting from the floor task. A static lifting task by Rocheford et al (2006) also revealed subjects favoring one side of the body upon exploration of GRFv when comparing those with previous unilateral injuries to those without.…”

Section: Discussionsupporting

confidence: 65%

“…Maines & Reiser (2006) also found consistent bilateral differences in GRFv between individual phases, as well as over the course of the entire lift, in a lifting from the floor task.…”

Section: Discussionmentioning

confidence: 64%

“…Further, assessment of forces in more than one plane, such as medial/lateral (GRFm/l) and anterior/posterior (GRFa/p), would have allowed for additional understanding of asymmetries during the squat exercise. Yet Maines & Reiser (2006) reported inconsistent GRFa/p in a crate-lifting task, stating that it may be due to the purpose of the force (balance in direction of the base of support), as Giakas, Baltzopoulous, Dangerfield, Dorgan, & Dalmira (1996) found GRFa/p to be highly variable between individuals and tasks.…”

Section: Discussionmentioning

confidence: 99%

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Effects of Fatigue on Bilateral Ground Reaction Force Asymmetries during the Squat Exercise

Hodges

Patrick

Reiser

2011

Journal of Strength and Conditioning Research

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OF THESIS EFFECTS OF FATIGUE ON BILATERAL GROUND REACTION FORCE ASYMMETRIES DURING THE SQUAT EXERCISEPhysical performance and risk for injury have been related to functional asymmetries of the lower extremity. The squat exercise is an important, functional movement serving as the major multi-joint, closed-chain lower extremity exercise in many strength and conditioning programs, as well as a large component in rehabilitation.Examinations of asymmetries during the squat exercise have revealed bilateral differences in the net joint torques, indicating unequal actions between the lower extremities. To date, no study has examined how fatigue affects these asymmetries. PURPOSE:The goal of this investigation was to examine functional bilateral asymmetries of the lower extremities during the squat exercise, exploring how they may change during the course of an individual set, as well as across multiple sets with fatigue.Based on a review of literature related to the effects of fatigue on functional asymmetries, it was hypothesized that asymmetries would increase with fatigue. METHODS:Seventeen recreationally trained men (n=9) and women (n=8) (mean ± SD age: 22.3 ± 2.5 yrs; height 170 ± 9.3 cm; mass 73.4 ± 13.8 kg) performed five sets of eight repetitions with 90% of their predetermined eight-repetition maximum (8RM 113 ± 35 % of their body mass). Anthropometric measurements and vertical ground reaction force (GRFv) data were collected. GRFv asymmetries were calculated by subtracting the % load on the iv right foot from that of the left foot. Initially highly symmetric subjects (± 1.7%) were removed from the analyses. The first two (R1&2) and last two (R7&8) repetitions of each set were examined. Eight subjects were reassessed for repeatability measures. RESULTS:R7&8 took longer to complete than R1&2 within a single set (p<0.001), however this finding was not observed across sets (p=0.867). The average asymmetry level across all sets for the absolute average was 4.3 ± 2.5% and 3.6 ± 2.3% for R1&2 and R7&8, respectively. There was no difference in whole group analysis (n=17) for any of the GRFv asymmetry analyses. Initially symmetric subjects were removed for the following analyses. For absolute peak instantaneous forces, the average asymmetry level across all sets was 3.8 ± 2.3% and 3.2 ± 2.3% for R1&2 and R7&8, respectively. Within a set, based on absolute asymmetry, levels of asymmetry dropped from beginning to end of a set (p=0.044). Exploring general shifts towards the left or right leg revealed a significant difference in peak instantaneous asymmetry with subjects becoming more symmetric with fatigue during the course of a single set (p=0.042). Of those who placed more weight on their right side at the beginning of a set, based on average asymmetry, a significant movement towards symmetry was seen for repetitions within a single set (p=0.036). Anthropometrics (segment lengths and circumferences) were generally not highly correlated to the asymmetries. Anthropometric measures were highly repeatable (Cronbac...

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Section: Discussionsupporting

confidence: 65%

“…Maines & Reiser (2006) also found consistent bilateral differences in GRFv between individual phases, as well as over the course of the entire lift, in a lifting from the floor task.…”

Section: Discussionmentioning

confidence: 64%

Section: Discussionmentioning

confidence: 99%

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Effects of Fatigue on Bilateral Ground Reaction Force Asymmetries during the Squat Exercise

Hodges

Patrick

Reiser

2011

Journal of Strength and Conditioning Research

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“…Other tasks shown to exhibit LEFA include double-leg landing (Schot et al, 1994), hang power clean (Lake et al, 2010), lifting from the ground (Maines & Reiser, 2006), loaded squatting (Flanagan et al, 2007;Hodges et al, 2011;Lake et al, 2011;Newton et al, 2006) and various jumping and hopping tasks (Ball et al, 2010;Barber-Westin et al, 2005;Hickey et al, 2009;Miyaguchi, 2010;Lawson et al, 2006;Newton et al 2006;Reiser et al 2003;Schiltz et al 2009;Stephens et al, 2007;Wong et al 2007). Because of this, it is well supported that LEFA exist in a normal otherwise healthy population and can be demonstrated in a variety of ways.…”

Section: Si=mentioning

confidence: 99%

“…While functional asymmetries during otherwise symmetric tasks might be expected in injured or physically disabled individuals, low levels of functional asymmetries have been found to be commonplace in healthy populations as well. Tasks in which this has been demonstrated include cycling (Daly & Cavanagh, 1976;Sanderson, 1990;Smak, Neptune & Hull, 1999), double-leg landing (Schot, Bates & Dufek ,1994), hang power clean (Lake, Lauder & Smith, 2010), lifting (Maines & Reiser, 2006), running (Vagenas & Hoshizaki,1992;Wong, Chamari, Chaouachi, Mao, Wisløff, & Hong, 2007), sit-to-stand (Lundin et al, 1995), loaded squatting (Flanagan & Salem, 2007;Hogdes, Patrick, & Reiser, 2011;Lake, Lauder & Smith, 2011;Newton, Gerber, Nimphius, Shim, Doan, et al, 2006), quiet standing (Blaszczyck, Prince, Raiche, Hebert, 2000;Rougier & Genthon, 2007), walking (Herzog, Nigg, Read & Olsson, 1989), and various jumping and hopping tasks (Ball, Stock, & Scurr, 2010;Barber-Westin, Galloway, Noyes, Corbett & Walsh, 2005;Hickey, Quatman, Myer, Ford, Brosky, & Hewett, 2009;Miyaguchi & Demura, 2010;Lawson, Stephens, Devoe & Reiser, 2006;Newton et al 2006;Reiser, Paulson, & Maines, 2003; performance (Schiltz et al, 2009;Riganas, Vrabas, Papaevangelou, Mandroukas, 2010), the way the fetus sits in the womb (Blustein & D'Amico, 1985), laterality of neural development (Gabbard & Hart, 1996;Myaguchi & Demura 2010) and fluctuating asymmetries, which are small deviations from bilateral symmetry as a result of random interactions with the environment (Trivers, Manning, Thornhill, Singh & Mcguire, 1999).…”

Section: Introductionmentioning

confidence: 99%

Relationships Between Asymmetries in Functional Movements and the Star Excursion Balance Test

Overmoyer¹,

Reiser

2013

Journal of Strength and Conditioning Research

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RELATIONSHIPS BETWEEN ASYMMETRIES IN FUNCTIONAL MOVEMENTS AND THE STAR EXCURSION BALANCE TESTLower extremity functional asymmetries (LEFA) as well as the Star Excursion Balance Test (SEBT) have been used to screen for injury risk and assess post-injury function. Both have also been shown to relate to physical performance. However, the relationships between LEFA, observed during different tasks, are not well understood, nor are the relationships between LEFA and side-to-side asymmetries in SEBT scores.As a result, it is difficult to determine which methods are most appropriate to assess detrimental asymmetries and whether they might be interchangeable. PURPOSE: The goal of this investigation was to examine the correlation in LEFA using measurement of vertical ground reaction forces (GRFv) during quiet standing, body weight squats, maximal effort counter-movement jumps (CMJ) and single-leg drop landings from a 30.5 cm platform (SLDL). Another goal was to investigate bilateral asymmetries in the SEBT anterior (Ant), posteromedial (PostMed) and posterolateral (PostLat) excursion directions, in both the correlations to each other and the correlations to the four functional movement tasks listed above. METHODS: Twenty recreationally active men (n=9) and women (n=11) (mean ± SD age: 21.9 ± 2.6 yrs; height 171 ± 8.8 cm; mass 67.2 ± 1.9 kg) performed three measured trials of each excursion direction of the SEBT, five 20 second quiet standing trials, five unloaded (body weight) squats, five CMJ and five SLDL on iii each side. Leg length measurements, GRFv data and SEBT scores for each leg were collected. Asymmetry was calculated by subtracting the % load on the preferred kicking leg (KL), or during the SEBT the percent of the bilaterally summed score on the KL, from that of the non-preferred kicking leg (NKL). Results were analyzed using Pearson's correlation and paired t-tests. Eleven subjects were reassessed for repeatability measures. RESULTS:Significant correlations (p<0.05) were found between asymmetries in several of the parameters measured in the LEFA tasks. Standing and average GRFv during CMJ significantly correlated to each other (r= 0.458); average GRFv during squats significantly correlated with standing GRFv (r= -0.452); both maximum and average GRFv during the squat significantly correlated with average and maximum GRFv during CMJ (r= -0.571 to -0.768). Average GRFv to peak in the SLDL significantly related to the squat (r= -0.494 to -0.500) and peak GRFv during the SLDL significantly related to CMJ average GRFv (r= -0.470). Further significance was identified among asymmetries in several SEBT excursion directions, particularly between the Ant versus PostMed (r= 0.406 to 0.564), and Ant versus PostLat (r= 0.470 to 0.570). There was a wide range of significant correlations in regards to combinations of these scores in the SEBT (r= 0.470 to 0.973). And finally, correlations were found to exist between several of the LEFA tasks and SEBT excursion directions. These included squats versus PostMed and Ant...

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Asymmetric loading of erector spinae muscles during sagittally symmetric lifting

et al. 2009

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Functional asymmetry is among the multitude of risk factors for low-back pain (LBP), the most common injury under general industrial and agricultural conditions. However, previous studies showed that normal healthy individuals exhibit some functional asymmetry, indicating that not all asymmetry causes LBP. Therefore, the threshold value that is able to discriminate between normal and pathological situations is used as critical information to predict LBP. As a preliminary study to find threshold, the purpose of this study is to quantify the magnitude of bilateral asymmetries of erector spinae muscle forces of a healthy group during sagittally symmetric lifting. Ten healthy male subjects with no history of back pathology participated in this study, which collected motion capture, force data, and electromyography signals from six infrared cameras (MCam2, Vicon), two force platforms (AMTI), and surface EMG (BME Korea). In order to quantify the magnitude of bilateral asymmetry in the trunk muscle forces, we used 3D linked segment and EMG-assisted modeling approaches, both of which were verified based on their recapitulation of previously-proposed models. The results indicated that each muscle force in the lumbar region exhibited asymmetry during the entire lifting process. In particular, the erector spinae muscle forces exhibited an approximate 24% difference between bilateral sites (p<0.05). The results of this study provided data from normal individuals by which to identify pathological situations and predict LBP incidence within general industrial and agricultural conditions.

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Ground reaction force bilateral asymmetries during submaximal sagittal plane lifting from the floor

Cited by 17 publications

References 25 publications

Effects of Fatigue on Bilateral Ground Reaction Force Asymmetries during the Squat Exercise

Effects of Fatigue on Bilateral Ground Reaction Force Asymmetries during the Squat Exercise

Relationships Between Asymmetries in Functional Movements and the Star Excursion Balance Test

Asymmetric loading of erector spinae muscles during sagittally symmetric lifting

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