Journal of Sports Science and Medicine
Journal of Sports Science and Medicine
ISSN: 1303 - 2968   
Ios-APP Journal of Sports Science and Medicine
Androit-APP Journal of Sports Science and Medicine
from September 2014
©Journal of Sports Science and Medicine ( 2002 ) 01 , 56 - 62

Review article
Developments in the Use of the Hamstring/Quadriceps Ratio for the Assessment of Muscle Balance
Rosalind Coombs , Gerard Garbutt
Author Information
School of Health Sciences, University of East London, Romford Road, Stratford, London, UK

Rosalind Coombs
✉ School of Health Sciences, University of East London, Romford Road, Stratford, London E15 4LZ, UK
Publish Date
Received: 23-04-2002
Accepted: 25-06-2002
Published (online): 01-09-2002
Share this article

Isokinetic moment ratios of the hamstrings (H) and quadriceps (Q) muscle groups, and their implication in muscle imbalance, have been investigated for more than three decades. The conventional concentric H/Q ratio with its normative value of 0.6 has been at the forefront of the discussion. This does not account for the joint angle at which moment occurs and the type of muscle action involved. Advances towards more functional analyses have occurred such that previous protocols are being re-examined raising questions about their ability to demonstrate a relationship between thigh muscle imbalance and increased incidence or risk of knee injury. This article addresses the function of the hamstring-quadriceps ratio in the interpretation of this relationship using the ratios Hecc/Qcon (ratio of eccentric hamstring strength to concentric quadriceps strength, representative of isolated knee extension) and Hcon/Qecc (ratio of concentric hamstring strength to eccentric quadriceps strength, representative of isolated knee flexion).

Key words: Muscle contraction, isokinetic, thigh, muscle balance

           Key Points

The Conventional H/Q Ratio

In clinical and scientific research, knee joint and thigh muscle function have conventionally been described using a variety of techniques. These include visual inspection of the moment-joint angle curve (Grace et al., 1984), the single point peak moment (Thorstensson et al., 1976), moment at a specified knee joint angle (Perrine and Edgerton, 1978; Thorstensson et al., 1976), and most commonly the hamstring-quadriceps peak moment ratio (Nosse, 1982; Kannus and Jarvinnen, 1990).

Angle specific moment curves represent the moment produced throughout the range of motion (ROM). The visual shape of such a curve can provide a template from which muscular and joint pathologies can be assessed and monitored through a rehabilitation regimen (Rothstein et al., 1987) and compared to the uninjured limb. They are displayed as either concentric or eccentric moments throughout the ROM for single muscle groups contracting at a given joint angular velocity (Figure 1).

Figure 1 presents data, which illustrates the difference in the moment production for the quadriceps and hamstring muscle groups throughout a 90° ROM. Similar patterns have been observed by others (Osternig et al., 1986; Westing and Seger, 1989; Aagaard et al., 2000). Angle-specific moment curves have proved useful in identifying and monitoring rehabilitation in pathologies such as chondromalacia patella in which peak moment ratios may be normal but decrements in moment may be present at other joint angles (Cabri and Clarys, 1991). They may also identify decrements in muscle function not apparent through analysis of peak moment alone (Osternig, 1986). However, angle specific moment curves do not account for the functioning of the antagonist, thereby not providing a comprehensive description of reciprocal muscle function.

The most frequently reported strength ratio of the muscles of the knee has been the concentric hamstring-quadriceps ratio (Hcon/Qcon). Steindler (1955) advanced the generalisation that absolute knee extension muscle force should exceed knee flexion force by a magnitude of 3:2 i.e. Hcon/Qcon of 0.66. Values ranging from 0.43-0.90 for this knee flexor-extensor ratio have been reported, although it is dependent on angular velocity, test position, population group and use of gravity compensation (see reviews by Nosse, 1982 and Kannus, 1994). There seems to be little consensus of a normative value for this conventional H/Q ratio, although 0.6 appears to have gained some general acceptance. For instance, Heiser et al. (1984) stated that injury prevention by detection of muscle imbalances should be based on a minimum Hcon/Qcon ratio of 0.60 at an angular velocity of 1.05 rad.s-1.

The use of peak moment ratios to describe normal knee function accounts for the main muscle groups of the thigh but has two major limitations. Firstly, the concentric quadriceps moment is normally compared with the concentric hamstring moment. This situation does not arise during functional movements. Instead, eccentric antagonist co-activation and serial elastic tension resist concentric agonist contraction eccentrically, or vice versa (Osternig et al., 1986). Secondly, they are normally cited irrespective of the joint angle at which they occur, which ignores the effect of muscle length. By failing to take into account the angle at which the moment is produced, erroneous conclusions may arise regarding the normal functioning of the muscle at joint angles other than that at which the observation occurs (Cabri and Clarys, 1991). Assessing muscle balance is considered important, but independently, the peak moment ratios and angle specific moment curves provide only a limited amount of information. A more functional approach to assessing muscle balance is required.

Evidence of Thigh Muscle Coactivation

It has been suggested that the role of the hamstring muscles during leg extension is to assist the anterior cruciate ligament (ACL) in preventing anterior tibial drawer forces (More et al., 1993; Yasuda and Sasaki, 1987), by increasing the posterior pull, increasing joint stiffness and reducing anterior laxity force during quadriceps loading to oppose it's force (Baratta et al., 1988). This helps in preventing overextension, decelerates the leg prior to full extension and stabilises the knee joint throughout the ROM (Baratta et al., 1988). The hamstrings play a key function in maintaining knee joint stability, especially where there is a deficient ACL. Tensile stress on the ACL is significantly reduced when the hamstrings and the quadriceps co-activate during extension, compared to quadriceps activation alone (Yasuda and Sasaki, 1987; Draganich and Vahey, 1990; More et al., 1993). Eccentric muscle actions, however, have a potential role in the aetiology of injuries in hamstring muscles, which are particularly prone to injury (Stanton and Purdam, 1989).

The cause of hamstring injuries is still unclear, although it has been suggested that muscle imbalance between the hamstring and quadriceps may predispose towards injury (Burkett, 1970; Grace et al., 1984). A 'normal' Hcon/Qcon ratio of 0.6 is frequently used as an injury prevention and rehabilitation tool (Baltzopoulos and Brodie, 1989; Kannus, 1994) but the reasoning behind its use does not relate to functional movements seen during both daily living and sporting activities. DeProft et al. (1988a, 1988b) showed that soccer players, who incorporated strength training into their normal soccer training, improved strength and kick performance significantly over non-footballers and those who trained normally. They suggested that in addition to their normal training, footballers should train their quadriceps concentrically and hamstrings eccentrically for improved kick performance. This implies that the relationship between eccentric hamstring and concentric quadriceps strength is important.

Co-activation of the quadriceps and hamstring muscles during isokinetic leg extension and flexion movements is evident in varying degrees at angular velocities up to 6.98 rad.s-1 (Osternig et al., 1986; Baratta et al., 1988; Amiridis et al., 1996; Kellis and Baltzopoulos, 1997; Aagaard et al., 2000). Osternig and co-workers (1986) measured integrated electromyographic activity (iEMG) of the quadriceps (vastus lateralis muscle) and hamstrings (biceps femoris muscle) with surface electrodes, simultaneously during continuous leg extension-flexion cycles performed at 1.75 rad.s-1 (100°.s-1) and 6.98 rad.s-1 (400°.s-1). Nine highly trained distance-runners and sprinters were analysed for antagonist co-activation during this continuous concentric activity. Muscle co-activation was calculated as the percentage of the mean iEMG activity from the same muscle group during its agonist phase. Greater iEMG of both antagonist muscles, the hamstrings during knee extension and the quadriceps during knee flexion, was observed for sprinters compared to distance runners, with generally higher mean muscle co-activation at 6.98 rad.s-1 compared to 1.75 rad.s-1. The hamstrings co-activated to a greater extent during agonist quadriceps contraction (8-59%) compared to the quadriceps during agonist hamstring contraction (5-8%). Amount of co-activation was dependent on angular velocity and type of training. This suggests that sport-specific muscle balance is required. Persons with a greater percentage of fast twitch fibres, such as sprint-trained athletes, may require greater muscle balance due to the explosiveness of the exercise undertaken. Higher H/Q ratio would represent greater balance, and of particular interest would be Hecc/Qcon due to the high quadriceps moment production observed during knee extension. An Hecc/Qcon ratio of 1.0 would be the recommendation. This point of equality is discussed in detail in the following section.

Quantification of antagonist activity has been extensively reviewed (Kellis, 1998) indicating that different methods are used to normalise antagonist activity, making it difficult to compare findings. For example, Baratta et al. (1988) normalised hamstring EMG activity during a concentric knee extension to the EMG of the same muscle during concentric knee flexion. Draganich et al. (1989) quantified antagonist EMG activity using the maximum isometric value for normalisation. Both showed approximately 10% maximal antagonist hamstring activity during a concentric knee extension. Physiologically, these methods of normalisation are incorrect (see review by Kellis (1998) for details). Antagonist EMG activity should be expressed relative to EMG activity of the same muscle when acting as agonist under eccentric conditions i.e. eccentric hamstring EMG during concentric knee extension normalised to eccentric hamstring EMG during eccentric knee extension. Using this methodological approach, higher antagonist hamstring EMG values of 20-30% have been reported (Donne and Luckwill, 1996; Kellis and Baltzopoulos, 1997; Aagaard et al., 2000). Eccentric hamstring activity has also been reported in a variety of activities in which knee extension occurs, including the soccer kick (Cabri and Clarys, 1991).

The question of co-activation in the form of a muscle ratio using iEMG with respect to muscle imbalance and injury has not been addressed. Muscle balance ratios that are easy to understand and interpret, and relate to the functional activities seen during sports, would be more relevant to athletes.

The Functional H/Q Ratio

The hamstring-quadriceps ratio has until recently been based on the concentric strength of these two muscle groups. Co-activation of these muscle groups is known to occur and takes place through opposing contraction modes. During leg extension the quadriceps contract concentrically (Qcon) and the hamstrings contract eccentrically (Hecc). Conversely, the hamstrings contract concentrically (Hcon) and the quadriceps eccentrically (Qecc) during leg flexion. Therefore, in order to accurately assess the balancing nature of the hamstrings about the knee joint the hamstring-quadriceps ratio should be described either as an Hecc/Qcon ratio representing knee extension, or an Hcon/Qecc ratio representing knee flexion.

Evaluation of isokinetic eccentric antagonistic strength relative to concentric agonist strength may provide a relationship of value in describing the maximal potential of the antagonistic muscle group. It might be more useful in determining an injury risk compared to the conventional Hcon/Qcon ratio. Dvir et al. (1989) was the first to report the Hecc/Qcon ratio and referred to it as a 'dynamic control ratio'. Since then the need to express the H/Q ratio functionally as an eccentric-concentric ratio has become more evident.

Donne and Luckwill (1996) reported an average Hecc/Qcon moment ratio throughout the ROM of 0.63 ± 0.07. They did not take into account muscle length, i.e. joint angle, in their analysis. Aagaard et al. (1995, 1998) considered joint angle and a change in angular velocity. They showed that the conventional H/Q ratio (i.e. Hcon/Qcon, Hecc/Qecc) was insensitive to changes in velocity between 0.52 rad. s-1 and 4.19 rad. s-1 (30°.s-1 and 240°.s-1), and between knee flexion angles of 0.52 rad and 0.87 rad (30° and 50°, where 0° represents full knee extension), values remaining between 0.47 and 0.56. In contrast, the functional Hecc/Qcon ratio increased above 1.00 with increasing velocity and more extended knee joint positions. The Hcon/Qecc ratio representative of knee flexion was considerably lower, decreasing from 0.60 to 0.28 with an increase in angular velocity. This is reasonable based on the lower maximal capacity of the hamstrings compared to the quadriceps. It has been suggested (Lestienne, 1979) that the greater mass of the quadriceps may provide a greater visco-elastic effect and hence an enhanced ability to passively control and decelerate the flexion motion. However, Lestienne (1979) did not correct for the effect of gravity. The reduced Hcon/Qecc simply reflects that the specific length-tension and force-velocity properties were impaired for the hamstring muscles and enhanced for the quadriceps muscles during fast forceful knee flexion.

Net (or resultant) joint moments are recorded on an isokinetic dynamometer, with contributing factors from both the agonist and antagonist muscle groups, and other muscles and ligaments that cross the joint. Gross muscle moments about the knee have been estimated using EMG recordings from the hamstrings and quadriceps (Kellis and Baltzopoulos, 1997; Aagaard et al., 2000). The actual antagonist moment exerted by the hamstring muscles during isolated isokinetic knee extension was calculated. For example, Aagaard et al. (2000) used 0.17 rad (10°) intervals over a 1.57 rad (90°) range of knee motion but did not present their findings in the form of an Hecc/Qcon ratio. If calculated, Aagaard et al. (2000) would have reported an increase in this moment ratio from 0.48 to 1.29 as the leg was extended.

Throughout the ROM the Hecc/Qcon ratio changes, whether using net or gross moments. There is a decrease in the concentric quadriceps moment from 90° of knee flexion to 0° (full extension) and a relatively constant eccentric hamstring moment, giving the increase in Hecc/Qcon at increasing angular velocity (Aagaard et al., 1995) and when approaching full knee extension (Aagaard et al., 1998). The length-tension properties of the quadriceps were gradually impaired at high velocities, reducing from 1.20-0.86 rad (69-49°), whereas the length-tension properties of the hamstrings remained unaltered at 0.37-0.44 rad (21-25°). This suggests that the eccentrically co-contracting hamstrings have a dynamic role in maintaining the stability of the knee during forceful knee extension. This agrees with the findings of Osternig et al. (1986) who showed that eccentric hamstring activation increased sharply in the last 0.44 rad (25°) of concentric knee extension. On average, 58% of the iEMG seen during hamstring agonist activity (i.e. during concentric knee flexion) was generated by the hamstrings during knee extension at the same joint angles.

An Hecc/Qcon ratio of 1.0, which we have labelled the point of equality, indicates that the eccentrically acting hamstrings have the ability to fully brake the action of the concentrically contracting quadriceps. During fast knee extension and towards full extension the eccentrically acting hamstrings have been shown to produce a braking joint flexor moment that is equal to or greater than the extensor moment exerted by the quadriceps (Aagaard et al., 1995, 1998). This would help to reduce anterior displacement of the tibia on the femur and prevent hyperextension of the knee. Where in the ROM this point of equality occurs may be of use as an indicator of normal function.

During everyday activities, the ACL is stressed in the first 45° of knee flexion then relaxes as the knee flexes further. During isokinetic exercise, varying amounts of ACL force or strain have been shown through a greater ROM, from full knee extension to 80° of flexion, although peak ACL force occurred at 35-40° (Toutoungi et al., 2000). The hamstring muscles function synergistically with the ACL (Yasuda and Sasaki, 1987; More et al., 1993) and hamstring co-contraction is effective during knee extension in decreasing anterior and rotary displacement of the tibia, from 15° to 80° of knee flexion (Hirokawa et al., 1991). So there may be a need for additional antagonistic hamstring activity and force as the knee flexes. It has been suggested that hamstring muscle activity during leg extension helps stabilise the joint throughout the ROM (Baratta et al., 1988). The aim of training would, therefore, be to shift the point of equality towards a more flexed knee joint position so there is increased potential for stability through a greater ROM. Ratios will vary depending on the relative strengths and weaknesses of the hamstrings and quadriceps, which would be determined by training, and possibly by genetics. It might be that in less explosive sports (i.e. not sprinting or multiple sprint sports) the position of the point of equality is less important.

Until experimental work is carried out, which can relate the point of equality to functional ability and injury risk, there is no solution to this question. It would be interesting to see where in the ROM changes in the ratio occur, and also what effect training has on temporal and quantitative activation of the hamstrings, and on other factors such as electromechanical delay.

Future Directions in the Use of the H/Q Ratio

Data published to date, which has analysed Hecc/Qcon or Hcon/Qecc ratios outside of this limited joint range of 0.52-0.87 rad of knee flexion, is minimal. This is surprising considering that the knee flexor optimum length for isometric torque production is known to occur at approximately a 0.35-0.52 rad (20-30°) joint angle and the knee extensor optimum between 1.05-1.22 rad (60-70°) (Westing and Seger, 1989).

It has been suggested that modelling the Hecc/Qcon relationship through a 90° range of knee extension motion may provide a necessary tool for analysing thigh muscle balance (Garbutt et al., 2001; Coombs et al., 2002). Further work from our laboratory using a different protocol to that previously used by Garbutt et al. (2001) and Coombs et al. (2002) has shown there is a continual rise in the Hecc/Qcon ratio when extending the leg compared to the relatively unchanged Hcon/Qcon ratio over the same range of motion (Figure 2).

This method of analysis may provide the basis of a model of normal knee function against which pathological states could be compared, helping in the understanding of the causes of hamstring and knee injury, and aiding the development of a preventative approach through correct training and rehabilitation.

The practical significance of the Hecc/Qcon ratio should be addressed in further work. Relating this ratio to functional tasks that are specific to a sport (i.e. a vertical jump for basketball players) may help identify if there is a weakness in the ROM, and a joint angle/muscle length that is more at risk of injury.


The use of the more functional H/Q ratio (Hecc/Qcon, Hcon/Qecc) proposed by Aagaard and colleagues (1995) is more physiologically and functionally sound than the conventional H/Q ratios (Hcon/Qcon, Hecc/Qecc) and thus more appropriate to use. Although the functional H/Q ratios account for the role of the antagonist in knee joint stabilisation at specific joint angles, they do not account for the hamstring-quadriceps relationship throughout the entire ROM. We have seen that this is important due to the difference in Hecc/Qcon and Hcon/Qcon throughout a 90° ROM (Figure 2).

Bilateral muscle asymmetry and muscle imbalances about the knee have been stated as the aetiology of many injuries, especially hamstring strains (Burkett, 1970). The question as to whether correction of any muscle imbalance could reduce the risk of injury, or if muscle imbalance causes injury, has not been fully investigated. The peak moment Hcon/Qcon ratio of 0.60 has previously been used to assess thigh muscle imbalance, but there is insufficient experimental evidence of its use as a predictor of injury. The analysis of the more functional H/Q ratios over the entire ROM and the positioning of the point of equality may help to address this unanswered question.


The authors would like to thank the reviewers for their valuable comments, which helped improve this manuscript for publication.


Journal of Sports Science and Medicine Rosalind Coombs
Employment: Researcher, School of Health Sciences, University of East London.
Research interests: Thigh muscle imbalance, sports injury, training and rehabilitation.

Journal of Sports Science and Medicine Gerard Garbutt
Employment: Professor and Head of School of Health Sciences, University of East London.
Research interests: Sports injury, rehabilitation and exercise testing
Journal of Sports Science and Medicine Aagaard P., Simonsen E.B., Andersen J.L., Magnusson S.P., Bojsen-Moller F., Dyhre-Poulsen P (2000) Antagonist muscle coactivation during isokinetic knee extension. Scandinavian Journal of Medicine and Science in Sports 10, 58-67.
Journal of Sports Science and Medicine Aagaard P., Simonsen E.B., Magnusson S.P., Larsson B., Dyhre-Poulsen P (1998) A new concept for isokinetic hamstring: quadriceps muscle strength ratio. American Journal of Sports Medicine 26, 231-237.
Journal of Sports Science and Medicine Aagaard P., Simonsen E.B., Trolle M., Bangsboo J., Klausen K (1995) Isokinetic hamstring/quadriceps ratio: influence from joint angular velocity, gravity correction and mode of contraction. Acta Physiologica Scandinavica 154, 421-427.
Journal of Sports Science and Medicine Amiridis I.G., Martin A., Morlon B., Martin L., Cometti G., Pousson M., van Hoecke J (1996) Co-activation and tension-regulating phenomena during isokinetic knee extension in sedentary and highly skilled humans. European Journal of Applied Physiology 73, 149-156.
Journal of Sports Science and Medicine Baltzopoulos V., Brodie D (1989) Isokinetic dynamometry: applications and limitations. Sports Medicine 8, 101-116.
Journal of Sports Science and Medicine Baratta R., Solomonow M., Zhou B.H., Letson D., Chuinard R., D'Ambrosia R (1988) Muscular coactivation: The role of the antagonist musculature in maintaining knee stability. American Journal of Sports Medicine 16, 113-122.
Journal of Sports Science and Medicine Burkett L (1970) Causative factors of hamstring strains. Medicine and Science in Sports and Exercise 2, 39-42.
Journal of Sports Science and Medicine Cabri J.M.H., Clarys J.P (1991) Isokinetic exercise in rehabilitation. Applied Ergonomics 22, 295-298.
Journal of Sports Science and Medicine Coombs R., Garbutt G., Cramp M (2002) Comparison of conventional and functional hamstring-quadriceps moment ratios through a 90° range of leg motion. Journal of Sports Sciences 20, 3-4.
Journal of Sports Science and Medicine DeProft E., Cabri J., Dufour W., Clarys J.P, Reilly T., Lees A., Davids K., Murphy W (1988a) Science & Football - Proceedings of the 1 World Congress of Science and Football. Strength training and kick performance in soccer players. London. E&FN Spon.
Journal of Sports Science and Medicine DeProft E., Clarys J.P., Bollens E., Cabri J., Dufour W, Reilly T., Lees A., Davids K, Murphy W (1988b) Science & Football - Proceedings of the 1 World Congress of Science and Football. Muscle activity in the soccer kick. London. E&FN Spon.
Journal of Sports Science and Medicine Donne B., Luckwill R.G (1996) Co-activation of quadriceps and hamstring muscles during concentric and eccentric isokinetic exercise. Isokinetics and Exercise Science 6, 21-26.
Journal of Sports Science and Medicine Draganich L.F., Jaeger R.J., Kralj A.R (1989) Coactivation of the hamstring and quadriceps during extension of the knee. Journal of Bone and Joint Surgery Am 71, 1075-1081.
Journal of Sports Science and Medicine Draganich L.F., Vahey J.W (1990) An. Journal of Orthopaedic Research 8, 57-63.
Journal of Sports Science and Medicine Dvir Z., Eger G., Halperin N., Shklar A (1989) Thigh muscle activity and anterior cruciate ligament insufficiency. Clinical Biomechanics 4, 87-91.
Journal of Sports Science and Medicine Garbutt G., Coombs R., Cramp M (2001) Functional hamstring/quadriceps moment ratio during isokinetic leg extension [abstract]. Proceedings of the 6 Annual Congress of the European College of Sport Science - 15 Congress of the German Society of Sport Science , 650-.
Journal of Sports Science and Medicine Grace T.G., Sweeter E.R., Nelson M.A., Ydens L.R., Skipper B.J (1984) Isokinetic muscle imbalance and knee-joint injuries. Journal of Bone and Joint Surgery Am 66, 734-740.
Journal of Sports Science and Medicine Heiser T.M., Weber J., Sullivan G., Clare P., Jacobs R.R (1984) Prophylaxis and management of hamstring muscle injuries in intercollegiate football players. American Journal of Sports Medicine 12, 368-370.
Journal of Sports Science and Medicine Hirokawa S., Solomonow M., Luo Z., Lu Y., D'Ambrosia R (1991) Muscular co-contraction and control of knee stability. Journal of Electromyography and Kinesiology 1, 199-208.
Journal of Sports Science and Medicine Kannus P. (1994) Isokinetic evaluation of muscular performance: Implications for muscle testing and rehabilitation. International Journal of Sports Medicine 15, 11-15.
Journal of Sports Science and Medicine Kannus P., Jarvinnen M (1990) Knee flexor and extensor strength ratios in follow up of acute knee distortion injuries. Archives of Physical Medicine and Rehabilitation 71, 38-41.
Journal of Sports Science and Medicine Kellis E (1998) Quantification of quadriceps and hamstring antagonist activity. Sports Medicine 25, 37-62.
Journal of Sports Science and Medicine Kellis E., Baltzopoulos V (1997) The effect of antagonist moment on the resultant joint moment during concentric and eccentric efforts of the knee extensors. European Journal of Applied Physiology 76, 253-259.
Journal of Sports Science and Medicine Lestienne F (1979) Effects of inertial load and velocity on the braking process of voluntary limb movements. Experimental Brain Research 35, 407-418.
Journal of Sports Science and Medicine More R.C., Karras B.T., Neiman R., Fritschy D., Woo SL-Y., Daniel D.M (1993) Hamstrings - an anterior cruciate ligament protagonist: an in vitro study. American Journal of Sports Medicine 21, 231-237.
Journal of Sports Science and Medicine Nosse L (1982) Assessment of selected reports on the strength relationship of the knee musculature. Journal of Orthopaedics and Sports Physical Therapy 4, 78-85.
Journal of Sports Science and Medicine Osternig L.N., Hamill J., Lander J.E., Robertson R (1986) Co-activation of sprinter and distance runner muscles in isokinetic exercise. Medicine and Science in Sport and Exercise 18, 431-435.
Journal of Sports Science and Medicine Osternig L.R (1986) Isokinetic dynamometry: implications for muscle testing and rehabilitation. Exercise and Sport Science Review 14, 45-80.
Journal of Sports Science and Medicine Perrine J.J., Edgerton V.R (1978) Muscle force-velocity and power-velocity relationships under isokinetic loading. Medicine and Science in Sports and Exercise 10, 159-166.
Journal of Sports Science and Medicine Rothstein J., Lamb R., Mayhew T (1987) Clinical uses of isokinetic measurements. Journal of Sports Physical Therapy 67, 1840-1844.
Journal of Sports Science and Medicine Stanton P., Purdam C (1989) Hamstring injuries in sprinting - the role of eccentric exercise. Journal of Orthopaedic and Sports Physical Therapy 10, 343-349.
Journal of Sports Science and Medicine Steindler A (1955) Kinesiology of the Human Body under Normal and Pathological Conditions. Springfield, Il. Charles C Thomas Publisher.
Journal of Sports Science and Medicine Thorstensson A., Grimby A.G., Karlsson J (1976) Force-velocity relationships and fibre composition in human knee extensors. Journal of Applied Physiology 40, 12-16.
Journal of Sports Science and Medicine Toutoungi D.E., Lu T.W., Leardini A., Catani F., O'Connor J.J (2000) Cruciate ligament forces in the human knee during rehabilitation exercises. Clinical Biomechanics 15, 176-187.
Journal of Sports Science and Medicine Westing S.H., Seger J.Y (1989) Eccentric and concentric torque-velocity characteristics, torque output comparisons, and gravity effect torque corrections for the quadriceps and the hamstring muscles in females. International Journal of Sports Medicine 10, 175-180.
Journal of Sports Science and Medicine Yasuda K., Sasaki T (1987) Muscle exercise after anterior cruciate ligament reconstruction: Biomechanics of the simultaneous isometric contraction method of the quadriceps and hamstrings. Clinical Orthopaedics 220, 266-274.
Home Issues About Authors
Contact Current Editorial board Authors instructions
Email alerts In Press Mission For Reviewers
Archive Scope
Supplements Statistics
Most Read Articles
  Most Cited Articles
JSSM | Copyright 2001-2018 | All rights reserved. | LEGAL NOTICES | Publisher

It is forbidden the total or partial reproduction of this web site and the published materials, the treatment of its database, any kind of transition and for any means, either electronic, mechanic or other methods, without the previous written permission of the JSSM.

This work is licensed under a Creative Commons License Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.