{"id":18,"date":"2025-02-20T18:06:00","date_gmt":"2025-02-20T18:06:00","guid":{"rendered":""},"modified":"2026-04-16T18:21:46","modified_gmt":"2026-04-16T18:21:46","slug":"back-squat-biomechanics-hypertrophy-and-anthropometry-part-ii","status":"publish","type":"post","link":"https:\/\/fitmia.fi\/?p=18","title":{"rendered":"Back squat biomechanics, hypertrophy and anthropometry Part II"},"content":{"rendered":"

 Part II<\/span><\/h3>\n

The anthropometry and biomechanics associated with
\nsquats are the topic of this second part, where I examine different squat
\npositions and their effects on different parts of the body. Demers et al. 2018,
\nGomes et al. 2020 have studied various physical characteristics, such as the
\nlength ratio of the legs and the flexibility of the joints in relation to
\nsquats. In particular, the ratio of the length of the femur and tibia became an
\nimportant factor, because in squats, the flexion and extension of the hip and
\nknee are carried out by the movement of the femur and tibia. A study by Demers
\n(2018) found that a higher femur-tibial ratio is associated with greater
\ndorsiflexion and knee flexion muscles, especially in squats with a narrow leg
\nposition. According to MacKea et al. (2012) used 3D kinematic analysis to
\ninvestigate possible differences in movement between men and women during
\nsquats. According to the study, men lean somewhat more forward, which gives the
\nspine movement and depth into a squat. Women, on the other hand, use the knees
\nand sacrum to achieve the depth of the squat, also using the hip flexion more
\nstrongly. The use of knees was more pronounced in women, and taller women had a
\nlarger knee angle than shorter women. Taller men, on the other hand, emphasized
\nsmaller hip angles. At least the benefit of the study is that men and women use
\ndifferent movement strategies in squats, in which case it should be taken into
\naccount in both coaching and rehabilitation. The purpose of the study of Kim et
\nal. (2021) was to investigate the relationships between physical
\ncharacteristics and lower limb biomechanics during squat movement. They were
\ntrying to find out whether there are also gender differences in these. They
\nmeasured the ratio of femoral to tibial length, mobility of hip and ankle
\njoints, and relative muscle strength. However, no significant gender difference
\nwas observed in these factors in this study. The biomechanics of the lower
\nlimbs have been shown to correlate more with relative muscle strength and joint
\nmobility than with the length ratio of the legs.<\/o:p><\/span><\/p>\n

Another interesting aspect of anthropometry is related
\nto the length of the femur. Cooke et al. (2019) studied the effects of
\nhamstring length on the number of repetitions of the squat movement. The result
\nwas that the subjects with the longest femur were able to do significantly
\nfewer repetitions than the subjects with the shortest femur. The results also
\nrevealed that body mass, fat percentage, and femoral length are all inversely
\nrelated to repetitions performed at 70% of 1RM in the back squat. Longer femoral
\nlimbs and longer muscle lengths also seem to be associated with greater muscle
\ndamage (Nogueira et al. 2011) and weakening of muscle function during
\ncontraction (Behrens et al. 2012). <\/span><\/p>\n<\/p>\n\n\n\n\n
<\/a><\/td>\n<\/tr>\n
Photo by Leon Ardho <\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n


<\/span><\/p>\n

The review of  <\/span>Escamilla
\net al. (2001) focused on the shear and compression forces of the lower leg and
\nfemur (tibiofemoral), the compression forces of the kneecap and femur
\n(patellofemoral), and the activity of the extensor and flexor muscles of the
\nknee. According to this, athletes with healthy knees can be recommended to
\nsquat horizontally (i.e. where the femur goes horizontally) instead of deep
\nsquats, because the risk of injury to the meniscus, cruciate ligaments and
\ncollateral ligaments may increase with deep squats. However, squats do not
\ncompromise the stability of the knee and can even increase stability when
\nperformed correctly. According to the review, squats are found to be an effective
\ndeveloper of hip, knee and ankle muscles, as it involves moderate to high
\nactivity in the muscles of the front thighs, hamstrings and calves. <\/o:p><\/span><\/p>\n

A wider squat position is recommended if the goal is
\nto optimize the development of hip adductors and hip extensors (e.g. gluteal
\nmuscles) (Miyamoto et al. 1999). A narrower squat position is more effective in
\ntargeting the development of the calf muscles (m. gastrocnemius) (Escamilla et
\nal. 2001). On the other hand, the squat position can also be varied to alter
\nthe forces related to the joints, since the narrow position helps to reduce the
\ncompressive forces (both patellofemoral and tibiofemoral). The wide squat
\nposition causes the smaller knee translation forward, reducing the shear forces
\n(Escamilla et al. 2001).<\/o:p><\/span><\/p>\n

Recommended squat technique to minimize risks<\/o:p><\/span><\/b><\/p>\n\n\n\n\n
\n

Gaze<\/o:p><\/span><\/b><\/p>\n<\/td>\n

\n

Backbone<\/o:p><\/span><\/b><\/p>\n<\/td>\n

\n

Depth<\/o:p><\/span><\/b><\/p>\n<\/td>\n

\n

Knee angle<\/o:p><\/span><\/b><\/p>\n<\/td>\n

\n

Feet<\/o:p><\/span><\/b><\/p>\n<\/td>\n<\/tr>\n

\n

Forward or up<\/o:p><\/span><\/p>\n<\/td>\n

\n

Neutral, straight, lumbar
\n lordosis <\/o:p><\/span><\/p>\n<\/td>\n

\n

Preservation
\n of lumbar lordosis as an indicator<\/o:p><\/span><\/p>\n<\/td>\n

\n

115\u00b0
\n to 125\u00b0<\/o:p><\/span><\/p>\n

Knees
\n freely over the feet during movement<\/o:p><\/span><\/p>\n

No
\n illumination, i.e. turning inward<\/o:p><\/span><\/p>\n<\/td>\n

\n

Neutral<\/o:p><\/span><\/p>\n

Heels on the ground<\/o:p><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/o:p><\/span><\/p>\n

Finally, it should be noted that in addition to the
\nsport-specific squat technique, athletes should also practice various squat
\nvariations for the sake of training variety, preventing overuse injuries, and
\nensuring progress. This also applies to other trainees: it is beneficial to
\nswitch up different positions and vary the use of machines and free weights. On
\nthe other hand, it is important to consider the trainee’s anthropometric
\ncharacteristics, so that the squat technique can be fine-tuned to their proportions,
\nmaking it an optimal and less risky exercise. For example, individuals with a
\ntorso-to-limb ratio shorter than average typically also have relatively longer
\nfemurs. The formula used to calculate the relative length of the femur has been
\napplied in some studies as follows: (femur length \/ total body length) x 100%.
\nThe typical relative femur length is 25%, and a larger number indicates that it
\nwill affect the biomechanics of the squat. A safe squat position in this case
\nwould be a narrower\/shoulder-width stance with a platform under the heels.
\nWeightlifting shoes with a raised heel work well too. This helps avoid harmful
\ncompressive and shear forces on the lumbar spine and sacroiliac joint,
\nalleviates pressure on the straightening of the lumbar lordosis and rounding of
\nthe lower back. The squat position thus remains more upright, with the back in
\na neutral position. All of this significantly reduces the risk of a herniated
\ndisc. On the other hand, squat depth can be influenced by a wider foot stance
\nif the goal is to achieve the deepest squat possible.<\/o:p><\/span><\/p>\n

 <\/o:p><\/span><\/p>\n

Photo: Squat (Photo by Leon Ardho from Pexels:
\nhttps:\/\/www.pexels.com\/photo\/photo-of-man-lifting-barbell-1552106\/)<\/o:p><\/span><\/p>\n

<\/p>\n

Refereces:<\/span><\/h4>\n

Anderson K & Behm DG (2005):
\nTrunk muscle activity increases with unstable squat movements<\/o:p><\/span><\/p>\n

Bazyler CD, Sato K, Wassinger
\nCA, Lamont HS, & Stone MH (2014): The efficacy of incorporating partial
\nsquats in maximal strength training<\/o:p><\/span><\/p>\n

Behrens M, Mau-Moeller A &
\nBruhn S (2012): Effect of exercise- induced muscle damage on neuromuscular
\nfunction of the quadriceps muscle<\/o:p><\/span><\/p>\n

Bryanton MA, Kennedy MD, Carey
\nJP & Chiu LZF (2012): Effect of squat depth and barbell load on relative
\nmuscular effort in squatting<\/o:p><\/span><\/p>\n

Cappozzo A, Felici F, Figura F
\n& Gazzani F (1985): Lumbar spine loading during half-<\/span>squat exercises<\/span><\/p>\n

Caterisano A, Moss RF,
\nPellinger TK, Woodruff K, Lewis VC, Booth W & Khadra T (2002): The effect
\nof back squat depth on the EMG activity of 4 superficial hip and thigh muscles<\/o:p><\/span><\/p>\n

Comfort P, McMahon JJ &
\nSuchomel TJ (2018): Optimizing squat technique-revisited<\/o:p><\/span><\/p>\n

Cooke DM,  Haischer MH, Carzoli JP, Bazyler CD, Johnson
\nTK, Varieur R, Zoeller RF, Whitehurst M & Zourdos MC (2019) : Body Mass and
\nFemur Length Are Inversely Related to Repetitions Performed in the Back Squat
\nin Well-Trained Lifters<\/o:p><\/span><\/p>\n

Delgado J, Drinkwater EJ, Banyard
\nHG, Haff GG & Nosaka K (2019): Comparison Between Back Squat,
\nRomanian Deadlift, and Barbell Hip Thrust for Leg and Hip Muscle Activities
\nDuring Hip Extension<\/o:p><\/span><\/p>\n

Demers E, Pendenza J, Radevich
\nV & Preuss R (2018): The effect of stance width and anthropometrics on
\njoint range of motion in the lower extremities during a back squat<\/o:p><\/span><\/p>\n

Escamilla RF (2001): Knee
\nbiomechanics of the dynamic squat exercise<\/o:p><\/span><\/p>\n

Escamilla, RF, Fleisig, GS,
\nLowry, TM, Barrentine, SW & Andrews, JR (2001): A three dimensional
\nbiomechanical analysis of the squat during varying stance widths<\/o:p><\/span><\/p>\n

Escamilla RF, Fleisig GS, Zheng
\nN, Barrentine SW, Wilke KE , & Andrews JR (1998): Biomechanics of the knee
\nduring closed kinetic chain and open kinetic chain exercises<\/o:p><\/span><\/p>\n

Escamilla RF, Fleisig GS,
\nZheng N, Lander JE, Barrentine SW, Andrews JR, Bergemann BW & Moorman CT (2001):
\nEffects of technique variations on knee biomechanics during the squat and leg
\npress<\/o:p><\/span><\/p>\n

Fry AC, Smith JC &
\nSchilling BK (2003): Effect of knee position on hip and knee torques <\/span>during the barbell squat<\/span><\/p>\n

Gomes J, Neto T, Vaz JR,
\nSchoenfeld BJ & Freitas SR (2020) Is there a relationship be- tween back
\nsquat depth, ankle flexibility, and Achilles tendon stiffness?<\/o:p><\/span><\/p>\n

Hartmann H, Wirth K, Klusemann M,
\nDalic J, Matuschek C & Schmidtbleicher D (2012) <\/span>Influence of squatting depth
\non jumping performance<\/span><\/p>\n

Kim S, Miller M, Tallarico A,
\nHelder S, Liu Y, Lee S (2021): Relationships between physical characteristics
\nand biomechanics of lower extremity during the squat<\/o:p><\/span><\/p>\n

Kubo K, Ikebukuro T & Yata H (2019): Effects of squat training with
\ndifferent depths on lower limb muscle volumes<\/span><\/p>\n

Mc Caw, ST, & Melrose DR (1999):
\nStance width and bar load effects on leg muscle activity during the parallel
\nsquat<\/span><\/p>\n

Mc Kean M & Burkett
\nBJ. (2012): Does Segment Length Influence the Hip, Knee and Ankle Coordination
\nDuring the Squat Movement?<\/span> <\/span><\/p>\n

Miyamoto K, Iinuma N, Maeda M,
\nWada E & Shimizu K (1999): Effects of abdominal belts on intra-abdominal
\npressure, intra- muscular pressure in the erector spinae muscles and
\nmyoelectrical activities of trunk muscles<\/span><\/p>\n

Miller JP, Sedory D &
\nCroce RV (1997): Leg rotation and vastus medialis oblique\/vastus <\/span>lateralis electromyogram
\nactivity ratio during closed chain kinetic exercises <\/span>prescribed for patellofemoral
\npain<\/span><\/p>\n

Ninos JC, Irrgang JJ, Burdett
\nR & Weiss JR (1997): Electromyographic analysis of the squat performed in
\nself-selected lower extremity neutral rotation and 30\u00b0 of lower extremity
\nturn-out from the self-selected neutral position<\/span> <\/span><\/p>\n

Nogueir AdeC, Vale RG, Gomes
\nAL & Dantas EH <\/span>(2011): The effect of muscle actions on the level of
\nconnective tissue damage<\/span><\/p>\n

Oddsson LIE, Persson T,
\nCresswell AG & Thorstensson A (1999): Interaction between voluntary and
\npostural motor commands during perturbed lifting<\/span><\/p>\n

Panerillo
\nRA, Backus SI & Parker JW <\/span>(1994): The effect of the squat exercise on
\nanterior-posterior knee translation in professional football players<\/span><\/p>\n

Plotkin DL, Rodas, MA,
\nVigotsky AD, McIntosh MC, Breeze E, Ubrik R, Robitzsch C, Agyin-Birikorang, A, Mattingly
\nML, Michel JM, Kontos NJ, Frug\u00e9 AD, Wilburn CM, Weimar WH, Adil Bashir A,
\nBeyers RJ, Henselmans M, Contreras BM & Roberts MD (2023): Hip thrust and
\nback squat training elicit similar gluteus muscle hypertrophy and transfer
\nsimilarly to the deadlift<\/span><\/p>\n

Ribeiro AS, Santos ED, Nunes JP, Nascimento MA,
\nGra\u00e7a \u00c1, Bezerra ES, Mayhew JL (2023): A Brief Review on the Effects of the
\nSquat Exercise on Lower-Limb Muscle Hypertrophy<\/span><\/p>\n

Signorile JF, Kwiatkowski K,
\nCaruso JF & Robertson B (1995): Effect of foot position on
\nelectromyographical activity of the superficial quadriceps muscles during the
\nparallel squat and knee extension<\/span><\/p>\n

Vakos JP, Nitz AJ, Threlkeld
\nAJ, Shapiro R & Horn T (1994): Electromyographic activity of <\/span>selected trunk and hip muscles
\nduring a squat lift. Effect of varying the lumbar <\/span>posture<\/span><\/p>\n

Weiss LW, Fry AC, Wood LE,
\nRelyea GE & Melton C (2000): Comparative effects of deep versus shallow
\nsquat and leg-press training on vertical jumping ability and related factors<\/span> <\/span><\/p>\n

Yack HJ, Collins CE & Whieldon
\nTJ (1993): Comparison of closed and open kinetic chain <\/span>exercise in the anterior
\ncruciate ligament-deficient knee<\/span><\/p>\n

 <\/o:p><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

 Part II The anthropometry and biomechanics associated with squats are the topic of this second part, where I examine different […]<\/p>\n","protected":false},"author":1,"featured_media":50,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[219],"tags":[111,112,113,114],"class_list":["post-18","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-training-information","tag-back-squat","tag-biomechanics","tag-squat","tag-squat-tecnique"],"jetpack_publicize_connections":[],"_links":{"self":[{"href":"https:\/\/fitmia.fi\/index.php?rest_route=\/wp\/v2\/posts\/18","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fitmia.fi\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fitmia.fi\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fitmia.fi\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fitmia.fi\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=18"}],"version-history":[{"count":3,"href":"https:\/\/fitmia.fi\/index.php?rest_route=\/wp\/v2\/posts\/18\/revisions"}],"predecessor-version":[{"id":147,"href":"https:\/\/fitmia.fi\/index.php?rest_route=\/wp\/v2\/posts\/18\/revisions\/147"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/fitmia.fi\/index.php?rest_route=\/wp\/v2\/media\/50"}],"wp:attachment":[{"href":"https:\/\/fitmia.fi\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=18"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fitmia.fi\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=18"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fitmia.fi\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=18"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}