Joseph J. Krzak, PT, Ph.D., PCS

Associate Professor

Midwestern University
College of Health Sciences
Physical Therapy Program
Alumni Hall 340C
555 31st St.
Downers Grove, IL 60515

Office: (630) 960-3942
Fax:     (630) 515-7224



Ph.D. Kinesiology, Nutrition, and Rehabilitation University of Illinois at Chicago 2013
B.S. Physical Therapy University of Illinois at Chicago 2000


Dr. Krzak's doctoral studies examined atypical foot and ankle motion during walking in youth with equinovarus and planovalgus deformity secondary to cerebral palsy (CP). His clinical area of interest includes working with children with neuromuscular and musculoskeletal disabilities that affect posture and movement.

Dr. Krzak's is a physical therapist whose overarching research goals are to: 1) use novel quantitative methods to explain why children with developmental disabilities move differently than typically developing children; and 2) develop and critically evaluate the effectiveness of therapeutic interventions to enhance functional mobility in children with neuromuscular and musculoskeletal disorders.

Research projects

Gait Dysfunction in Cerebral Palsy 

Cerebral palsy (CP) describes a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. CP is considered the most prevalent physical disability of childhood with an incidence of 3.6 per 1000 children. The clinical progression of CP results in atypical posturing and movement, characteristic locomotor (gait) deviations, and an increase in energy cost of 1.3 times to that of aged-matched peers during walking and gross motor tasks. Quantitative gait analysis typically includes collection of temporal-spatial, kinematic, kinetic and electromyographic (EMG) data during locomotion.  Quantitative gait analysis has been extensively utilized across ages and pathologies to guide clinicians' decisions about appropriate interventions, providing objective data about the efficacy of orthopedic surgery, and longitudinally tracking the progression of various disease processes.  The overall objective of this line of research is to quantitatively evaluate gait deviations in children with CP, as well as, to critically evaluate the effectiveness of therapeutic and surgical interventions to improve their gait.    

Selected Publications

Flanagan A, Krzak J, Peer M, Urban M, Johnson P. Evaluation of short-term intensive orthotic garment use in children who have cerebral palsy. Pediatr Phys Ther. 2009 Summer; 21(2):201-4.

Graf A, Hassani S, Krzak J, Caudill A, Flanagan A, Bajorunaite R, Harris G, Smith P. Gait characteristics and functional assessment of children with type I osteogenesis imperfecta. J Orthop Res. Sep 2009;27(9):1182-1190.

Graf A, Hassani S, Krzak J, Long J, Caudill A, Flanagan A, Eastwood D, Kuo KN, Harris G, Smith P. Long-term outcome evaluation in young adults following clubfoot surgical release. J Pediatr Orthop. Jun 2010;30(4):379-385.

Slavens BA, Graf A, Krzak J, Vogel L, Harris GF. Upper extremity wheelchair kinematics in children with Spinal Cord Injury. Conf Proc IEEE Eng Med Biol Soc. 2011:8158-8161.

Krzak J, Graf A, Caudill A, Flanagan A, Smith P, and Harris GF.  Analysis of Push-Off Power during Locomotion in Children with Type 1 Osteogenesis Imperfecta. Journal of Experimental and Clinical Medicine. 2011;3(5):195-199.

Konop K, Strifling K, Krzak J, Graf A, Harris, GF. Upper Extremity Joint Dynamics during Walker Assisted Gait:  A Quantitative approach towards Rehabilitative Intervention. Journal of Experimental and Clinical Medicine. 2011;3(5):213-217.

Hassani S, Krzak J, Flanagan A, Bagley A, Gorton G, Romness M, Tykowski C, Abel M, Johnson B, Oeffinger D. Assessment of Strength and Function in Ambulatory Children with Cerebral Palsy by GMFCS level and Age: A Cross-sectional Study.  Critical Reviews in Physical and Rehabilitation Medicine.  2011;23(1):1-14.

Flanagan A, Krzak J, Hassani S, Bagley A, Gorton G, Romness M, Tykowski C, Abel M, Johnson B, Oeffinger D. Relationships among Strength, Body Composition and Measures of Activity in Ambulatory Children with Cerebral Palsy: A Cross-sectional Study. Critical Reviews in Physical and Rehabilitation Medicine. 2011;23(1):15-29.

Graf A, Wu KW, Smith PA, Kuo KN, Krzak J, Harris G. Comprehensive review of the functional outcome evaluation of clubfoot treatment: a preferred methodology. J Pediatr Orthop B. Jan 2012;21(1):20-27.

Krzak JJ, Corcos DM, Graf A, Smith P, Harris GF. Effect of Fine Wire Electrode Insertion on Gait Patterns in Children with Hemiplegic Cerebral Palsy." Gait Posture, Feb 2013;37(2):251-257.

Ackman J, Altiok H, Flanagan A, Peer M, Graf A, Krzak J, Hassani S, Eastwood D, Harris GF.  Long-term follow up of Van Nes Rotationplasty for congenital proximal focal femoral deficiency.  J Bone Joint Surg Br 2013;95-B:192-198.

Cohen T, Altiok H, Wang M, McGrady L, Tarima S, Krzak J, Graf A, Smith P, Harris G.  Evaluation of cast creep occurring during simulated clubfoot correction.  Proc Inst Mech Eng H 2013;227(8):917-925.

Anissipour AK, Hammerberg KW, Caudill A, Kostiuk T, Tarima S, Zhao HS, Krzak JJ, Smith PA.  Behavior of scoliosis during growth in children with Osteogenesis Imperfecta. J Bone Joint Surg; 2014 Feb 5;96(3):237-43.

Hassani S, Krzak JJ, Johnson B, Flanagan A,  Gorton G, Bagley A, Õunpuu S, Romness M, Tylkowski C, Oeffinger D. One Minute Walk Test and Timed Up & Go in Ambulatory Children with Diplegic Cerebral Palsy: Performance and Minimum Clinically Importance Differences. Dev med Child Neurol. 2014;56(5):482-9.

Smith PA, Kuo KN, Graf AN, Krzak JJ, Flanagan A, Hassani S, Caudill AK, Dietz FR, Morcuende J, Harris GF. Long-term Results of Comprehensive Clubfoot Release Versus the Ponseti Method: Which Is Better?  Clin Orthop Relat Res. 2014;Apr;472(4):1281-90.

Udoekwere UI, Krzak JJ, Graf A, Hassani S, Tarima S, Riordan M, Sturm P, Hammerberg K, Gupta P, Anissipour A, Harris GF.  Effect of posterior spinal fusion to different levels on trunk mobility in individuals with adolescent idiopathic scoliosis.  Spine Deformity; 2014;2(4):291-300.

Krzak JJ, Graf A, Altiok H. Quantitative assessment of the foot and ankle during locomotion. Turkish Association of Orthopaedics and Traumatology; 2014; 13:351-364.

 Rammer JR, Krzak JJ, Riedel SA, Harris GF.  Evaluation of upper extremity movement characteristics during standardized pediatric functional assessment with a Kinect®-based markerless motion analysis system. Conf Proc IEEE Eng Med Biol Soc. 2014 Aug;2014:2525-8. doi: 10.1109/EMBC.2014.6944136 [Epub ahead of print]. PMID: 25570504  

Schnorenberg AJ, Slavens BA, Graf A, Krzak J, Vogel L, Harris GF. Upper extremity biomechanics of children with spinal cord injury during wheelchair mobility. Conf Proc IEEE Eng Med Biol Soc. 2014 Aug;2014:4338-41. doi: 10.1109/EMBC.2014.6944584 [Epub ahead of print]. PMID:25570952  

Slavens B, Schnorenberg AJ, Aurit C, Graf A, Krzak JJ, Reiners H, Vogel LC, Harris GF. Evaluation of pediatric manual wheelchair mobility using advanced biomechanical methods. BioMed Research International. 2015; 3(137): 1-16.  

Krzak JJ, Corcos DM, Damiano DL, Graf A, Hedeker, D, Smith PA, Harris GF. Kinematic foot types in youth with equinovarus secondary to hemiplegia. Gait Posture; 2015; 41:402-408. 

Kuo KN, Wu KW, Krzak JJ, Smith PA. Tendon transfers around the foot: When and Where. Foot and Ankle Clinics of North America.2015 Dec;20(4):601-17.  

Kurapati N, Krzak JJ, Graf A, Hassani S, Tarima S, Sturm PF, Hammerberg KW, Gupta P, Harris GF. Effect of surgical fusion on volitional weight-shifting in individuals with Adolescent Idiopathic Scoliosis. Spine Deformity.2016; 4:432-438.  

Altiok H, Riordan A, Graf A, Krzak J, Hassani S.  Response of scoliosis in children with myelomeningocele to surgical release of tethered spinal cord.  Top Spinal Cord Inj Rehabil. 2016; 22(4): 247-252.  

AlHuthaifi F, Krzak JJ, Hanke T, Vogel LC. Predictors of Motor Outcomes in Adults with Spinal Cord Injury Following Inpatient Rehabilitation: A Systematic Review. The Journal of Spinal Cord Medicine. 2017; May 40(3): 282-294.  

Kruger KM, Konop KA, Krzak JJ, Graf A, Altiok H, Smith PA, Harris GF.  Segmental Kinematic Analysis of Planovalgus Feet in Children with Cerebral Palsy. Gait and Posture. 2017; 54:277-283.

Graf A, Kuo KN, Kurapati NT, Krzak JJ, Hassani S, Caudill A, Flanagan A, Harris GF, Smith PA.  A Long Term Follow-up of Young Adults with Idiopathic Clubfoot: Does foot morphology relate to pain? Journal of Pediatric Orthopaedics.2017; [ePub ahead of print].

Garman C, Graf A, Krzak JJ, Caudill AK, Smith PA, Harris GF.  Gait deviations in children with osteogenesis imperfect types I, III, and IV. Journal of Pediatric Orthopaedics. 2017; [ePub ahead of print].  

Cech D, Krzak JJ, Anderson DK. Linking the essential core competencies in entry-level pediatric physical therapy education curriculum: a case report. Journal of Physical Therapy Education. 2017; 31(4): 89-94.

Thompson SV, Cech D, Cahill S, Krzak JJ. Linking the Pediatric Evaluation of Disability-Computer Adaptive Test (PEDI-CAT) to the International Classification of Function.  Pediatric Physical Therapy. Pediatr Phys Ther. 2018 Mar 1. [Epub ahead of print].