In the powerlifting deadlift, you use a grip where one hand is pronated and the other supinated. Earlier studies have noted differences in muscle activation between grips in upperbody excersices, but how the grip effects the muscle activation in the deadlift has not been investigated and it is not known if using the same grip over time can cause muscular imbalance or injuries. The purpose of the study was too is to investigate if there is a difference in force distribution and development between the left and right leg with a double pronated, dominant and non-dominant under-/overhand grip in the deadlift exercise. Subjects were 10 competitive powerlifters consisting of 7 men and 3 women. Testing was performed on two force plates measuring ground reaction force with one leg on each plate. The lifters did 2 lifts with each grip with 80% of their 1RM in the conventional deadlift. Peak force, time to peak force, force impulse and values at the same time as the total peak force was analyzed for each side. Peak force for the total force curve was also analyzed. The result showed one significant value between grips: The mean difference between the two sides at the same point as the total peak force showed a significans of P=0,02. Significant values were also found in force impulse (P=0,03) and values at total peak force (P=0,04) when analyzing lift one and two for the dominant grip between each other. This study shows that using the same over-/underhand grip does not affect force production or bilateral differences and is only a matter of comfort. However, it is hard to draw a conclusion and future testing should involve complementary methods to be able to state if there are differences and how these present themselves.

This study examined muscle activation and relative joint angles during a conventional deadlift while using either a double‐pronated or overhand/underhand (OU) grip. Ten weight‐trained individuals performed the deadlift with 60% and 80% of their 1‐repetition maximum, with three different grip variations. EMG recordings were taken of the left and right biceps brachii, brachioradialis, upper trapezius, and upper latissimus dorsi. Motion capture was used to measure angles of the wrist, elbow, knee, and hip. With an OU grip, significant bilateral asymmetry was seen in EMG activity of biceps brachii and brachioradialis. Mean wrist and elbow angle also showed significant bilateral asymmetry when using an OU grip. Training recommendations for the OU grip deadlift should emphasize the need to vary which hand is supinated/pronated to avoid muscle imbalances and possible injury. Furthermore, it may be preferential to use a double‐pronated grip to avoid asymmetric training altogether.

Dentre os fatores relacionados ao treinamento, a escolha do exercício representa um dos aspectos menos abordados na literatura especializada. Ainda que seja determinante para a implementação do treinamento, tendo em vista que se trata do vetor a partir dos quais as adaptações neuro-musculares irão ocorrer, pouco se tem estudado acerca de suas características biomecânicas. O presente estudo objetivou caracterizar as ações de músculos do membro inferior durante a execução do levantamento terra no estilo convencional (LT) e na sua variação com os joelhos estendidos (LTJE). No protocolo proposto as variáveis relativas a atividade muscular foram registradas através de sistema de aquisição EMG 1000 (Lynx Inc). Para cada um dos músculos analisados - bíceps femoral (BF), vasto lateral (VL), multifido lombar (ML), tibial anterior (TA) e gastrocnêmio medial (GM) - foram analisados parâmetros relativos ao nível de máxima ativação durante o movimento, ao padrão temporal de ativação e ao tempo de contração. Para o nível de máxima ativação durante o LT, o BF (1,001±0,247U.A), VL (1,283±0,339U.A), (1,127±0,427U.A), TA (1,040±0,188U.A), GM (1,0385±0,120U.A) apresentaram variações discretas e não significativas (p<0,05). quando comparados com o LTJE, onde o BF apresentou (0.986±0,285U.A), o VL (1,011±0,146U.A), ML (1,060±0,205U.A), TA (1,092±0,153U.A), GM (1,083±0,163U.A). Comportamento semelhante foi verificado para o tempo de contração. As ausências de diferenças significativas evidenciam que os dois movimentos não apresentam estruturas diferentes, pois o comportamento temporal, intensidade de ativação muscular e tempo de ativação são semelhantes, o que mostra efetividade na utilização destes como estratégia de implementação em programas de treinamento e de reabilitação física. / Among the factors related to the training, the exercise choice represents one of the aspects less boarded in specialized literature. Yet it is determinative for the training implementation and considering it attends the vector that from it the neuromuscular adaptations will occur, and its biomechanical characteristics have been little studied. The present study aimed at characterizing the actions of selected muscles of the inferior member during the execution of the deadlift in the conventional style (LT) and its variation with the extended knees (LTJE). In the proposed protocol the variants of EMG have been registered by the acquisition system EMG1000 (Lynx Inc). For each analized muscle – lateral hamstring (BF), lateral vastus (VL), multifidus lumbar (ML), anterior tibia (TA) and medial gastrocnemius (GM) – were analized parameters related to the maximum activation level during the movement, to activation time standard and to contraction time. For the maximum activation level during the LT, the BF (1,001±0,247U.A), VL (1,283±0,339U.A), (1,127±0,427U.A), TA (1,040±0,188U.A), GM (1,0385±0,120U.A) have been presented discrete variations without significant differences (p<0,05), when compared with the LTJE, where the BF presented (0.986±0,285U.A), the VL (1,011±0,146U.A), ML (1,060±0,205U.A), TA (1,092±0,153U.A), GM (1,083±0,163U.A). The same result was verified for the contraction time. The absence of significant differences makes evident that both movement didn’t present different structures, therefore the activation time standard, the maximum muscular activation and contraction time were equal, what it shows effectiveness in the use of these as strategy of implementation in programs of training and physical rehabilitation.

Dentre os fatores relacionados ao treinamento, a escolha do exercício representa um dos aspectos menos abordados na literatura especializada. Ainda que seja determinante para a implementação do treinamento, tendo em vista que se trata do vetor a partir dos quais as adaptações neuro-musculares irão ocorrer, pouco se tem estudado acerca de suas características biomecânicas. O presente estudo objetivou caracterizar as ações de músculos do membro inferior durante a execução do levantamento terra no estilo convencional (LT) e na sua variação com os joelhos estendidos (LTJE). No protocolo proposto as variáveis relativas a atividade muscular foram registradas através de sistema de aquisição EMG 1000 (Lynx Inc). Para cada um dos músculos analisados - bíceps femoral (BF), vasto lateral (VL), multifido lombar (ML), tibial anterior (TA) e gastrocnêmio medial (GM) - foram analisados parâmetros relativos ao nível de máxima ativação durante o movimento, ao padrão temporal de ativação e ao tempo de contração. Para o nível de máxima ativação durante o LT, o BF (1,001±0,247U.A), VL (1,283±0,339U.A), (1,127±0,427U.A), TA (1,040±0,188U.A), GM (1,0385±0,120U.A) apresentaram variações discretas e não significativas (p<0,05). quando comparados com o LTJE, onde o BF apresentou (0.986±0,285U.A), o VL (1,011±0,146U.A), ML (1,060±0,205U.A), TA (1,092±0,153U.A), GM (1,083±0,163U.A). Comportamento semelhante foi verificado para o tempo de contração. As ausências de diferenças significativas evidenciam que os dois movimentos não apresentam estruturas diferentes, pois o comportamento temporal, intensidade de ativação muscular e tempo de ativação são semelhantes, o que mostra efetividade na utilização destes como estratégia de implementação em programas de treinamento e de reabilitação física. / Among the factors related to the training, the exercise choice represents one of the aspects less boarded in specialized literature. Yet it is determinative for the training implementation and considering it attends the vector that from it the neuromuscular adaptations will occur, and its biomechanical characteristics have been little studied. The present study aimed at characterizing the actions of selected muscles of the inferior member during the execution of the deadlift in the conventional style (LT) and its variation with the extended knees (LTJE). In the proposed protocol the variants of EMG have been registered by the acquisition system EMG1000 (Lynx Inc). For each analized muscle – lateral hamstring (BF), lateral vastus (VL), multifidus lumbar (ML), anterior tibia (TA) and medial gastrocnemius (GM) – were analized parameters related to the maximum activation level during the movement, to activation time standard and to contraction time. For the maximum activation level during the LT, the BF (1,001±0,247U.A), VL (1,283±0,339U.A), (1,127±0,427U.A), TA (1,040±0,188U.A), GM (1,0385±0,120U.A) have been presented discrete variations without significant differences (p<0,05), when compared with the LTJE, where the BF presented (0.986±0,285U.A), the VL (1,011±0,146U.A), ML (1,060±0,205U.A), TA (1,092±0,153U.A), GM (1,083±0,163U.A). The same result was verified for the contraction time. The absence of significant differences makes evident that both movement didn’t present different structures, therefore the activation time standard, the maximum muscular activation and contraction time were equal, what it shows effectiveness in the use of these as strategy of implementation in programs of training and physical rehabilitation.

Marklyft är en övning som effektivt tränar bland annat höftextensorer, som är en av de viktigaste muskelgrupperna för att utföra ett vertikalhopp. Trots detta har inga studier gjorts på korrelationen mellan marklyft och vertikalhopp, däremot finns flertalet studier gjorda på korrelation mellan knäböj och vertikalhopp. Syftet med denna studie var att undersöka eventuella samband mellan marklyft - vertikalhopp, vertikalhopp - BMI (Body Mass Index) och marklyft - BMI hos friska fysioterapeutstudenter (n = 15) på Uppsala Universitet. Detta för att undersöka om marklyft skulle kunna användas som alternativ träning för att förbättra personers vertikalhopp. Vertikalhopp mättes med elektronisk hoppmatta och marklyft med 1RM-test. BMI räknas ut med deltagarnas längd och vikt. Variablerna sammanställdes och sambandet räknades ut via Pearsons korrelationskoefficient. Resultaten visade ingen korrelation mellan vertikalhopp och marklyft (p = 0,773, r = 0,083) och en svag negativ korrelation för BMI och vertikalhopp (p = 0,514, r = -0,188). En mycket stark positiv korrelation mellan BMI och marklyft (p = 0,013, r = 0,721) påträffades, där de med högre BMI lyfte mer i marklyft. Slutsatsen av studien resulterar i att marklyft inte borde rekommenderas som en alternativ övning för att förbättra vertikalhoppsförmågan. Dock behövs fler studier med bland annat fler deltagare för att vidare undersöka eventuella kliniska tillämpningar. / Deadlift is an exercise that proves to effectively train the hip extensors amongst other muscle groups, which is one of the most important muscle groups for performing a vertical jump. Despite this connection, no studies have been made on the correlation between deadlifts and vertical jumps, contrary to the numerous studies made regarding the correlation between squat and vertical jump. The purpose of this study was to examine the possible correlation between deadlifts, vertical jumps as well as BMI (Body Mass Index) amongst healthy physiotherapy students (n=15) at Uppsala University. This to assess the use of deadlift as an alternative training method to improve a person’s vertical jump ability. Vertical jumps were measured with an electronic jump mat and deadlifts were measured with 1RM-test. BMI was calculated using the person’s height and weight. The variables were then compiled and calculated using Pearson's correlation coefficient. The results presented no correlation between vertical jumps and deadlifts (p = 0,773, r = 0,083), and a weak negative correlation between BMI and vertical jumps (p = 0,514, r = -0,188). A very strong positive correlation between BMI and deadlifts (p = 0,013, r = 0,721) was detected, whereas participants with higher BMI lifted more in deadlift. The conclusion of this study dictates that deadlift should not be recommended as an alternative exercise to improve vertical jump ability. However, more studies with larger populations are needed to scrutinize clinical applications.

This study examined the postactivation potentiation effects of combining squat and deadlift exercises on subsequent repeated jump performance. Fifteen, resistance-Trained youth wrestlers were randomly allocated to either undertake back squats (BSq), deadlift (DL) or BSq and DL as supersets (BSq+DL), with a repeated jump protocol performed 8-minutes post-exercise in each session. Thereafter, a control condition (CON) was completed involving a general warm-up, followed by the repeated jump protocols. Power outputs, flight time, contact time and reactive strength index were recorded from each repeated jump protocol. Measures were compared between the BSq, DL and BSq+DL sessions and between sessions that generated the best power output (BEST) with CON via inferential statistics and effect size (ES) calculations. The BSq condition exhibited significantly greater power output compared to the CON condition (p0.05, ES = 1.07), although no differences were identified for the other conditioning activities. Furthermore, power output, flight time and reactive strength index were significantly greater for the BEST compared to the CON condition (p0.05, ES = 0.97-1.47). Results indicated that BSq was the optimal conditioning activity to increase power output during a repeated jump protocol. However, greater improvement during the BEST condition suggests that the type of conditioning activity should also be considered on an individual-basis.

The purpose of the study was to determine anthropometric characteristics that may affect deadlift performance. Fourteen powerlifters performed isometric pulls on a force plate at 3 key positions of the deadlift (at the floor, just above the patella, and 5-6 cm short of lockout) and the mid-thigh pull (MTP). RM ANOVA revealed that forces generated at each bar height differed significantly (F(3,39) = 51.058, p<0.05). Discriminant analysis was able to classify lifters into "stronger" and "weaker" groups with 100% accuracy using measured anthropometric dimensions. Stepwise discriminant analysis revealed that height to body mass ratio was important in differentiating performance in all positions but lockout. Segment and various measures of height were also important in discriminating performance in the knee, lockout, and MTP positions. Results of this analysis should provide some insight to the anthropometric dimensions that are related to success in various phases of the deadlift.

In sports, peaking phases are often applied prior to important competitions. Peaking phases typically consist of a planned overreach followed by a taper ending with a few days of complete rest. However, during peaking phases, components of body composition such as body mass (BM), fat mass (FM), fat-free mass (FFM), and skeletal muscle mass (SMM) have been shown to be negatively impacted, which could compromise performance outcomes. Thus, the purpose of this study was to monitor body composition prior to and immediately after a peaking phase to determine if body composition changes occurred. Twelve powerlifters completed a seven-week training protocol designed to peak powerlifting performance. The first four weeks consisted of strength training designed to standardize participant training prior to the first testing session (T1). Following T1, the participants performed a one-week overreach followed by a one-week step-taper ending with 2 and 4 days of complete rest followed by a second testing session (T2). Each testing session consisted of a) measuring BM, FM, FFM, and SMM via bioelectrical impedance, and b) 1-repetition maximum (1RM) testing on back squat (BS), bench press (BP), and deadlift (DL). 1RM performances were summed together for a Powerlifting Total (PT), and Wilks Scores were applied to determine relative performance changes. There were no statistically significant changes in BM (p > 0.99), FM (p > 0.99), FFM (p > 0.99), or SMM (p > 0.99), suggesting a maintenance of body composition during the peaking phase. There were, however, statistically significant changes in 1RM-BS (p = 0.04), PT (p = 0.05), and Wilks Score (p = 0.02). These data suggest that two-week peaking phase can result in the maintenance of body composition alongside improvements in strength performance.

Disability due to low back pain is common. While evidence exist that exercise is effective in reducing pain and disability, it is still largely undetermined which kind of exercises that are most effective. The overall aim of this thesis was to evaluate and compare the effects of a high-load lifting exercise and individualized low-load motor control exercises for patients with nociceptive mechanical low back pain. A secondary aim was to evaluate which patients benefit from training with a high-load lifting exercise. All four papers in this thesis were based on a randomized controlled trial including 70 participants with nociceptive mechanical low back pain as their dominating pain pattern. Participants were randomized into training with either a high-load lifting exercise (HLL), the deadlift, (n=35) or individualized low-load motor control exercises (LMC) (n=35). Both interventions included aspects of pain education. All participants were offered twelve sessions during an eight week period. The effects of the interventions were evaluated directly after and twelve months after the end of the intervention period. Outcome measures were pain intensity, activity, disability, physical performance, lumbo-pelvic alignment and lumbar multifidus muscle thickness. There was a significant between-group effect in favour of the LMC intervention regarding improvements in activity, movement control tests and some tests of trunk muscle endurance. For pain intensity there were no significant differences between groups. A majority of participants in both intervention groups showed clinically meaningful improvements from baseline to two and twelve month follow-up regarding pain intensity and activity. There were no significant differences between HLL and LMC regarding the effect on lumbo-pelvic alignment or lumbar multifidus thickness. The participants who benefit the most from the HLL intervention were those with a low pain intensity and high performance in the Biering-Sørensen test at baseline. The results of this thesis showed that the HLL intervention was not more effective than the LMC intervention. The LMC was in fact more effective in improving activity, performance in movement control tests and some tests of trunk muscle endurance, compared to the HLL intervention. The results imply that the deadlift, when combined with education, could be considered as an exercise to produce clinically relevant improvements on pain intensity in patients who prefer a high-load exercise. However, before considering deadlift training, the results suggest that pain intensity and performance in the Biering-Sørensen test should be evaluated.

Titel: The comparative study of predication equations for value calculation 1-RM at the squat and the dead lift. Aim: To evaluate the most exact equation for the calculation 1-RM on the basis of comparation of extracted data with predication equations at the squat and the dead lift. Research complex: The research complex is created by the soldiers of Army of Czech Republic. They are the men at the age from 20 to 40 with health classification A. Used methods: The comparative method with the using of experimental testing. Results: By the mutual comparation of data we have found out, that the most exact predication equation for the calculation 1-RM in a squat or in a dead lift is from the authors O'Conner et al. Squat was predicted with correlation coefficient r = 0.975 and deadlift with a value of r = 0.951. Keywords: sqaut, dead lift, 1-RM, prediction equation, correlation coefficient.