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Laura A. Frey Law, MPT, MS, PhD

Associate Professor of Physical Therapy and Rehabilitation Science

Contact Information

Primary Office
1-246 Medical Education Building (MEB)
Iowa City, IA 52242


BSE, Biomedical Engineering, The University of Iowa
MPT, Physical Therapy, The University of Iowa
MS, Bioengineering, The University of Michigan
PhD, Physical Rehabilitation Science, The University of Iowa

Licensure and Certifications

Physical Therapy #03133 - Iowa Department of Public Health Bureau of Professional Licensure (Board of Physical and Occupational Therapy)

Research Summary

My research follows two primary lines of investigation: 1) Factors that contribute to pain heterogeneity including: sex, psychological traits, genetics, activity level, etc. To study this question, we use experimental pain models in humans: intramuscular infusion of an acidic phosphate buffer into the anterior tibialis muscle, cold pressor task (hand immersion in ice water), or isolated muscle fatigue (isometric contraction to failure). We also utilize surveys of pain perceptions and self-reported personality responses. In particular we are focusing on why women appear to have a higher risk of referred pain with the muscle pain model (~80%) whereas men are less likely to experience referred pain (~45%) despite similar local infusion-site pain. 2) Strength and fatigue research: We are working with the Virtual Soldier Research (VSR) group to develop mathematical models of normal strength and fatigue, using both static and dynamic strength indices. In addition we are studying whether clear differences in fatigue with aging, by muscle group, or between sexes exist, and the potential interactions between these variables.


Wang, D., Merkle, S. L., Lee, J. E., Sluka, K. A., Rakel, B. A., Graven-Nielsen, T. & Frey Law, L. A. (2020). Multisensory sensitivity is related to deep-tissue but not cutaneous pain sensitivity in healthy individuals. J Pain Res, 2020, 2493-2508. DOI: 10.2147/JPR.S267972.

Carlesso, L. C., Frey Law, L. A., Wang, N., Nevitt, M., Lewis, C. E. & Multicenter Osteoarthritis Study Group, (2020). The association of pain sensitization and conditioned pain modulation to pain patterns in knee osteoarthritis. Arthritis Care Res (Hoboken). PMID: 32882103.

Stefanik, J. J., Frey-Law, L. A., Segal, N. A., Niu, J., Lewis, C. E., Nevitt, M. C. & Neogi, T. (2020). The relation of peripheral and central sensitization to muscle co-contraction: the MOST study. Osteoarthritis Cartilage, 28(9), 1214-1219. PMID: 32585174.

Master, H., Neogi, T., Callahan, L. F., Nelson, A. E., LaValley, M., Cleveland, R. J., Golightly, Y. M., Thoma, L. M., Zhang, Y., Voinier, D., Christiansen, M. B., Jakiela, J. T., Nevitt, M., Lewis, C. E., Frey Law, L. A. & White, D. K. (2020). The association between walking speed from short- and standard-distance tests with the risk of all-cause mortality among adults with radiographic knee osteoarthritis: Data from three large United States cohort studies. Osteoarthritis Cartilage, S1063-4584(20), 31119-5. PMID: 32861851.

Mueller, M., Chimenti, R. L., Merkle, S. & Frey Law, L. A. (2020). Accelerometry analysis options produce large differences in lifestyle physical activity measurement. Physiol Meas, 41(6), 065006. PMID: 32434175.

Looft, J. M., Frey-Law, L. A. (2020). Adapting a fatigue model for shoulder flexion fatigue: Enhancing recovery rate during intermittent rest intervals. J Biomech, 106, 109762. PMID: 32517992.

Sisante, J., Wang, N., Felson, D. T., Nevitt, M. C., Lewis, C. E., Frey Law, L. A. & Segal, N. A. (2020). Influence of antagonistic hamstring coactivation on measurement of quadriceps strength in older adults. PM R, 12(5), 470-478. PMID: 31585496.

Cheema, N., Frey Law, L. A., Naderi, K., Lehtinen, J., Slusallek, P. & Hamalainen, P. (2020). Predicting Mid-Air Interaction Movements and Fatigue Using Deep Reinforcement Learning. pp. 1-13. CHI '20: Proceedings of the 2020 CHI Conference on Human Factors in Computing Systems. DOI: 10.1145/3313831.3376701.

Merkle, S. L., Sluka, K. A. & Frey-Law, L. A. (2020). The interaction between pain and movement. J Hand Ther, 33(1), 60-66. PMID: 30025839.

Neelapala, Y. V., Bhagat, M. & Frey-Law, L. A. (2020). Conditioned Pain Modulation in Chronic Low Back Pain: A Systematic Review of Literature. Clin J Pain, 36(2), 135-141. PMID: 31764164.

Carlesso, L. C., Segal, N. A., Frey Law, L. A., Zhang, Y., Na, L., Nevitt, M., Lewis, C. E. & Neogi, T. (2019). Pain Susceptibility Phenotypes in Those Free of Knee Pain with or at Risk of Knee Osteoarthritis: The Multicenter Osteoarthritis Study. Arthritis Rheumatol, 71(4), 542-549. PMID: 30307131.

Sluka, K. A., Frey-Law, L. A. & Hoeger Bement, M. (2018). Exercise-induced pain and analgesia? Underlying mechanisms and clinical translation. Pain, 159(Suppl 1), S91-S97. PMID: 30113953.

Merriwether, E. N., Frey-Law, L. A., Rakel, B. A., Zimmerman, M. B., Dailey, D. L., Vance CGT,, Golchha, M., Geasland, K. M., Chimenti, R., Crofford, L. J. & Sluka, K. A. (2018). Physical activity is related to function and fatigue but not pain in women with fibromyalgia: baseline analyses from the Fibromyalgia Activity Study with TENS (FAST). Arthritis Res Ther, 20(1), 199. PMID: 30157911.

Looft, J. M., Herkert, N. & Frey-Law, L. A. (2018). Modification of a three-compartment muscle fatigue model to predict peak torque decline during intermittent tasks. J Biomech, 77, 16-25. PMID: 29960732.

Chimenti, R. L., Frey-Law, L. A. & Sluka, K. A. (2018). A mechanism-based approach to physical therapist management of pain. Phys Ther, 98(5), 302-314. PMID: 29669091.

Ellingson, L. D., Hibbing, P. R., Kim, Y., Frey-Law, L. A., Saint-Maurice, P. F. & Welk, G. J. (2017). Lab-based validation of different data processing methods for wrist-worn ActiGraph accelerometers in young adults. Physiol Meas, 38(6), 1045-1060. PMID: 28481750.

Carlesso, L. C., Segal, N. A., Curtis, J. R., Wise, B. L., Frey Law, L. A., Nevitt, M. & Neogi, T. (2017). Knee pain and structural damage as risk factors for incident widespread pain: Data from the Multicenter Osteoarthritis study. Arthritis Care & Res (Hoboken), 69(6), 826-832. PMID: 27636245.

Carlesso, L. C., Niu, J., Segal, N. A., Frey Law, L. A., Lewis, C. E., Nevitt, M. C. & Neogi, T. (2017). The Effect of Widespread Pain on Knee Pain Worsening, Incident Knee Osteoarthritis (OA), and Incident Knee Pain: The Multicenter OA (MOST) Study. J Rheumatol, 44(4), 493-498. PMID: 28250143.

Merkle, S., Frey Law, L. A. (2017). Self-reported physical activity is related to less pressure pain sensitivity but not to acute muscle pain. J Pain, 18(4), S87.

Frey Law, L. A., Sluka, K. A. (2017). How does physical activity modulate pain?. Pain, 158(3), 369-370. PMID: 28135214.

Felson, D. T., Niu, J., Quinn, E. K., Neogi, T., Lewis, C., Lewis, C. E., Frey Law, L. A., McCulloch, C., Nevitt, M. & LaValley, M. (2017). Multiple Nonspecific Sites of Joint Pain Outside the Knees Develop in Persons With Knee Pain. Arthritis Rheumatol, 69(2), 335-342. PMID: 27589036.

Frey Law, L. A., Whitis, A. M. & Stockdale, C. K. (2017). Experimental pain sensitivity in women with vestibulodynia: a pilot study. Proc Obstet Gynecol, 7(1), Article 3 [8 p.].

Hussain, S. J., Frey Law, L. A. (2016). 3D strength surfaces for ankle plantar- and dorsi-flexion in healthy adults: an isometric and isokinetic dynamometry study. J Foot Ankle Res, 9, 43. PMID: 27843491.

Frey-Law, L. A., Bohr, N. L., Sluka, K. A., Herr, K., Clark, C. R., Noiseux, N. O., Callaghan, J. J., Zimmerman, M. B. & Rakel, B. A. (2016). Pain sensitivity profiles in patients with advanced knee osteoarthritis. Pain, 157(9), 1988-99. PMID: 27152688.

Feinstein, J. S., Khalsa, S. S., Salomons, T. V., Prkachin, K. M., Frey-Law, L. A., Lee, J. E., Tranel, D. & Rudrauf, D. (2016). Preserved emotional awareness of pain in a patient with extensive bilateral damage to the insula, anterior cingulate, and amygdala. Brain Struct Funct, 221(3), 1499-1511. PMID: 25577137.

Merriwether, E., Rakel, B., Dailey, D., Alemo Munters, L., Darghosian, L., Abdelhamid, R., Vance, C. G., Frey Law, L. A., Allen, L., Crofford, L. & Sluka, K. A. (2016). Monocyte phenotype is associated with physical activity and pain outcomes in women with fibromyalgia. J Pain, 17(4), S95. DOI: org/10.1016/j.jpain.2016.01.289.

Merkle, S., Greimann, E., Paul, C. & Frey Law, L. A. (2016). Pain sensitivity is associated with vigorous physical activity and high cardiorespiratory fitness. J Pain, 17(4), S21-S22. DOI: 10.1016/j.jpain.2016.01.087.

Dailey, D. L., Frey Law, L. A., Vance, C. G., Rakel, B. A., Merriwether, E. N., Darghosian, L., Golchha, M., Geasland, K. M., Spitz, R., Crofford, L. J. & Sluka, K. A. (2016). Perceived function and physical performance are associated with pain and fatigue in women with fibromyalgia. Arthritis Res Ther, 18, 68. PMID: 26979999.

Neogi, T., Guermazi, A., Roemer, F., Nevitt, M. C., Scholz, J., Arendt-Nielsen, L., Woolf, C., Niu, J., Bradley, L. A., Quinn, E. & Frey Law, L. A. (2016). Association of joint inflammation with pain sensitization in knee osteoarthritis: The Multicenter Osteoarthritis Study. Arthritis Rheumatol, 68(3), 654-61. PMID: 26554395.

Frey Law, L. A., George, S. (2016). Individual Differences and Pain Variability. In K. A. Sluka (Eds.) In: Clinical Management of Pain for Physical Therapists, 2nd Edition. Seattle Washington: IASP Press.

Segal, N. A., Nevitt, M. C., Welborn, R. D., Nguyen, U. S., Niu, J., Lewis, C. E., Felson, D. T. & Frey Law, L. A. (2015). The association between antagonist hamstring coactivation and episodes of knee joint shifting and buckling. Osteoarthritis Cartilage, 23(7), 1112-1121. PMID: 25765501.

Neogi, T., Frey-Law, L. A., Scholz, J., Niu, J., Arendt-Nielsen, L., Woolf, C., Nevitt, M., Bradley, L. & Felson, D. T. (2015). Sensitivity and sensitisation in relation to pain severity in knee osteoarthritis: trait or state?. Ann Rheum Dis, 74(4), 682-688. PMID: 24351516.

Frey Law, L. A. (2015). Modeling Muscle Strength and Fatigue. In , K. Abdel-Malek (Eds.) In: Digital Human Modeling.

Looft, J. M., Frey Law, L. A. (2015). Modelling three-dimensional human strength capacity: logistic vs. polynomial surface equations. International Journal of Human Factors Modelling and Simulation (IJHFMS), 5(1), 5-18. DOI: 10.1504/IJHFMS.2015.068122.

Xia, T., Frey Law, L. A. (2015). Wrist joint torque-angle-velocity envelope evaluation and modeling. International Journal of Human Factors Modelling and Simulation (IJHFMS), 5(1), 33-52. DOI: 10.1504/IJHFMS.2015.068120.

Avin, K. G., Tumulura, A., Looft, J. & Frey Law, L. A. (2015). Strength Loss Counteracts Age-related Improvements in Muscle Fatigue Properties when Considering Functional Task Endurance–A Modeling Study. Gerontol Geriatr Res, 4(3), 1000218. DOI: 10.4172/2167-7182.1000218.

Glass, N. A., Segal, N. A., Sluka, K. A., Torner, J. C., Nevitt, M. C., Felson, D. T., Bradley, L. A., Neogi, T., Lewis, C. E. & Frey Law, L. A. (2014). Examining Sex Differences in Knee Pain: The Multicenter Osteoarthritis Study. Osteoarthritis Cartilage, 22(8), 1100-1106. PMID: 24999111.

Maxwell, J. L., Felson, D. T., Niu, J., Wise, B., Nevitt, M. C., Singh, J. A., Frey Law, L. A. & Neogi, T. (2014). Does clinically important function after knee replacement guarantee good absolute function? The multicenter osteoarthritis study. J Rheumatol, 41(1), 60-64. PMID: 24293582.

Frey Law, L. A., Lee, J., Wittry, A. & Melyon, M. (2013). Pain rating schema: Three distinct subgroups of individuals emerge when rating mild, moderate and severe pain. J Pain Res, 7, 13-23. PMID: 24379696.

Gregory, N. S., Gibson-Corley, K., Frey Law, L. A. & Sluka, K. A. (2013). Fatigue-enhanced hyperalgesia in response to muscle insult: induction and development occur in a sex-dependent manner. Pain, 154(12), 2668-76. PMID: 23906552.

Maxwell, J. L., Keysor, J. J., Niu, J., Singh, J. A., Wise, B. L., Frey Law, L. A., Nevitt, M. C. & Felson, D. T. (2013). Participation Following Knee Replacement: The MOST Cohort Study. Phys Ther, 93(11), 1467-1474. PMID: 23813082.

Frey Law, L. A., Avin, K. G. (2013). Muscle coactivation: A generalized or localized motor control strategy?. Muscle Nerve, 48(4), 578-585. PMID: 24037745.

Glass, N. A., Torner, J. C., Frey Law, L. A., Wang, K., Yang, T., Nevitt, M. C., Felson, D. T., Lewis, C. E. & Segal, N. A. (2013). The Relationship between Quadriceps Muscle Weakness and Worsening of Knee Pain in the MOST Cohort: a 5-Year Longitudinal Study. Osteoarthritis Cartilage, 21(9), 1154-1159. PMID: 23973125.

Lee, J. E., Watson, D. & Frey Law, L. A. (2013). Psychological factors predict local and referred experimental muscle pain: A cluster analysis in healthy adults. Eur J Pain, 17(6), 903-915. PMID: 23165778.

Frey Law, L. A. (2013). Strength and Fatigue: Experiments and Modeling. In K. A. Abdel-Malek , J. S. Arora (Eds.) Human Motion Simulation: Predictive Dynamics. pp. 127-147. DOI: 10.1016/B978-0-12-405190-4.00006-4.

Frey Law, L. A., Laake, A., Avin, K., Heitsman, J. & Adel-Malek, K. (2012). Knee and Elbow 3D Strength Surfaces: Peak Torque–Angle–Velocity Relationships. J Appl Biomech, 28(6), 726-737. PMID: 22813601.

Frey Law, L. A., Looft, J. M. & Heitsman, J. (2012). A three-compartment muscle fatigue model accurately predicts joint-specific maximum endurance times for sustained isometric tasks. J Biomech, 45(10), 1803-1808. PMID: 22579269.

Stefanik, J. J., Roemer, F. W., Zumwalt, A. C., Zhu, Y., Gross, K. D., Lynch, J. A., Frey Law, L. A., Lewis, C. E., Guermazi, A., Powers, C. M. & Felson, D. T. (2012). Association between measures of trochlear morphology and structural features of patellofemoral joint osteoarthritis on MRI: the MOST study. J Orthop Res, 30(1), 1-8. PMID: 21710542.

Avin, K. G., Frey Law, L. A. (2011). Age-related differences in muscle fatigue vary by contraction type: A Meta-analysis. Phys Ther, 91(8), 1153-1165. PMID: 21616932.

Frey Law, L. A., Krishnan, C. & Avin, K. G. (2011). Modeling nonlinear errors in surface electromyography due to baseline noise: a new methodology. J Biomech, 44(1), 202-205. PMID: 20869716.

Frey Law, L. A., Lee, J. E., McMullen, T. & Xia, T. (2010). Relationships between maximum holding time and ratings of pain and exertion differ for static and dynamic tasks. Appl Ergon, 42(1), 9-15. PMID: 20462566.

Avin, K., Naughton, M. R., Ford, B. W., Moore, H. E., Monitto, M. N., Stark, A. M., Gentile, A. J. & Frey Law, L. A. (2010). Sex Differences in Fatigue Resistance Are Muscle Group Dependent. Med Sci Sports Exerc, 42(10), 1943-1950. PMID: 20195184.

Stefanik, J. J., Zhu, Y., Zumwalt, A. C., Gross, K. D., Klancy, M., Lynch, J. A., Frey Law, L. A., Lewis, C. E., Roemer, F. W., Powers, C. M., Guermazi, A. & Felton, D. T. (2010). Association between patella alta and the prevalence and worsening of structural features of patellofemoral joint osteoarthritis: the multicenter osteoarthritis study. Arthritis Care Res (Hoboken), 62(9), 1258-1265. PMID: 20506169.

Lee, J. E., Watson, D. & Frey Law, L. A. (2010). Lower-order pain-related constructs are more predictive of cold pressor pain ratings than higher-order personality traits. J Pain, 11(7), 681-691. PMID: 20356801.

Rakel, B., Cooper, N., Adams, H. J., Messer, B. R., Frey Law, L. A., Dannen, D. R., Miller, C. A., Polehna, A. C., Ruggle, R. C., Vance, C. G., Walsh, D. M. & Sluka, K. A. (2010). A new transient sham TENS device allows for investigator blinding while delivering a true placebo treatment. J Pain, 11(3), 230-238. PMID: 19945354.

Frey Law, L. A., Avin, K. G. (2010). Endurance time is joint-specific: a modeling and meta-analysis investigation. Ergonomics, 53(1), 109-129. PMID: 20069487.

Abdel-Malek, K., Arora, J., Yang, J., Marlar, T., Beck, S., Swan, C., Frey Law, L. A., Kim, J., Bhatt, R., Mathai, A., Murphy, C., Rahmatalla, S., Patrick, A. & Obusek, J. P. (2009). A Physics-Based Digital Human Model. Int J Veh Des, 51(3-4), 324-340. DOI: 10.1504/IJVD.2009.027960.

Frey Law, L. A., George, S. (2009). Individual Differences and Pain Variability. In K. A. Sluka (Eds.) In: Clinical Management of Pain for Physical Therapists. Seattle Washington: IASP Press.

Frey Law, L. A., Sluka, K. A., McMullen, T., Lee, J., Arendt-Nielsen, L. & Graven-Nielsen, T. (2008). Acidic buffer induced muscle pain evokes referred pain and mechanical hyperalgesia in humans. Pain, 140(2), 254-264. PMID: 18835099.

Xia, T., Frey Law, L. A. (2008). A theoretical approach for modeling peripheral muscle fatigue and recovery. J Biomech, 41(14), 3046-3052. PMID: 18789445.

Frey Law, L. A., Evans, S., Knudtson, J., Nus, S., Scholl, K. & Sluka, K. A. (2008). Massage reduces pain perception and hyperalgesia in experimental muscle pain: a randomized control trial. J Pain, 9(8), 714-21. PMID: 18455480.

Rahmatalla, S., Xia, T., Contratto, M., Kopp, G., Wilder, D., Frey Law, L. A. & Ankrum, J. (2008). Three-dimensional motion capture protocol for seated operator in whole body vibration. Int J Indust Ergon, 38(5-6), 425-433. DOI: 10.1016/j.ergon.2007.08.015.

Frey Law, L. A., Xia, T. & Laake, A. (2008). Modeling Human Physical Capability: Joint Strength and Range of Motion. In V. Duffy (Eds.) In: Handbook of Digital Human Modeling. Taylor & Francis Group/CRC Press.

Frey Law, L. A., Shields, R. K. (2007). Mathematical models of human paralyzed muscle after long-term training. J Biomech, 40(12), 2587-2589. PMID: 17316653.

Shields, R. K., Dudley-Javoroski, S. & Frey Law, L. A. (2006). Electrically-induced muscle contractions influence bone density decline after spinal cord injury. Spine (Phila Pa 1976), 31(5), 548-553. PMID: 16508550.

Frey Law, L. A., Shields, R. K. (2006). Predicting human chronically paralyzed muscle force: a comparison of three mathematical models. J Appl Physiol (1985), 100(3), 1027-36. PMID: 16306255.

Frey Law, L. A., Shields, R. K. (2005). Mathematical models use varying parameter strategies to represent paralyzed muscle force properties: a sensitivity analysis. J Neuroeng Rehabil, 2(12). PMID: 15927064.

Frey Law, L. A., Shields, R. K. (2005). Predicting human paralyzed soleus muscle force properties using three mathematical muscle models. Med Sci Sports Exerc, 37(5).

Dudley-Javoroski, S., Frey Law, L. A. & Shields, R. K. (2005). Electrically-induced muscle contractions attenuate bone loss after spinal cord injury. Med Sci Sports Exerc, 37(5).

Frey Law, L. A., Shields, R. K. (2004). Femoral loads during passive, active, and active-resistive stance after spinal cord injury: a mathematical model. Clin Biomech (Bristol, Avon), 19(3), 313-21. PMID: 15003348.

Frey Law, L. A. (2003). Executive Corner: Exactly how do you pull together a campus-wide research forum?. (Vols. 3). (4), pp. 2. The Graduate Bulletin.

Frey Law, L. A., Haftel, H. M. (1998). Shoulder, knee, and hip pain as initial symptoms of juvenile ankylosing spondylitis: a case report. J Orthop Sports Phys Ther, 27(2), 167-174. PMID: 9475141.

Shields, R. K., Frey Law, L., Reiling, B., Sass, K. & Wilwert, J. (1997). Effects of electrically induced fatigue on the twitch and tetanus of paralyzed soleus muscle in humans. J Appl Physiol (1985), 82(25), 1499-1507. PMID: 9134899.

Frey Law, L. A., Smidt, G. L. (1996). Underwater forces produced by the hydro-tone bell. J Orthop Sports Phys Ther, 23(4), 267-271. PMID: 8775372.

Trombitas, K., Frey Law, L. A. & Pollack, J. (1993). Filament lengths in frog semitendinosis and tibialis anterior muscle fibres. J Muscle Res Cell Motil, 14(2), 167-172. PMID: 8315020.