Effects of Pressure Biofeedback Unit Application on Muscle Strength and Balance in Total Knee Arthroplasty Patients during Exercise for Strengthening the Knee Extensor Muscle

무릎 폄근 강화 운동 동안 압력 생체되먹임 장비 적용이 무릎관절 전치환술 환자들의 근력과 균형에 미치는 영향

  • Park, Jin (Center of Musculoskeletal, Drimsol Hospital) ;
  • Park, Han-Kyu (Dept. of Physical Therapy, Dongju College)
  • 박진 (드림솔병원 근골격계센터) ;
  • 박한규 (동주대학교 물리치료과)
  • Received : 2021.01.05
  • Accepted : 2021.02.05
  • Published : 2021.02.28


Purpose : The purpose of this study is to verify the effect of selective muscle strengthening of the knee joint extensor muscles using a pressure biofeedback unit to improve knee extensor strength and the balance ability of total knee replacement patients. Through this, we tried to provide clinical information. Methods : In this study, 12 patients with total knee replacement were recruited from a rehabilitation hospital. They were divided into two groups: a feedback group (n=6) and a control group (n=6). All patients received 30 minutes of continuous passive motion and leg-strengthening exercises for 15 minutes five times a week for two weeks. Subjects performed knee extension exercises with or without biofeedback units in the sitting position. The knee extensor strength and balance ability were measured before and after exercise. Knee extensor strength was measured by Biodex system 3 and balance ability was measured by Balancia software. Results : Both the experimental group and the control group showed a significant difference in the muscle strength of the knee joint extensor muscles after intervention (p<.05). In comparison, the experimental group showed a significant difference than the control group (p<.05). Both the experimental group and the control group showed a significant difference in the velocity average, path length, area 95 % center of pressure (COP), weight distribution, five times sit to stand test (FTSST) after intervention. In comparison, the experimental group showed a significant difference in velocity average, area 95 % COP, and FTSST than the control group (p<.05). Conclusion : In order to strengthen the knee extensor muscle and improve the balance ability in total knee replacement patients, it is necessary to consider providing pressure biofeedback unit during leg strengthening exercises.


  1. Ahn JO, Weon JH, Koh EK, et al(2020). Effectiveness of hamstring stretching using a pressure biofeedback unit for 4 weeks: a randomized controlled trial. Hong Kong Physiother J, 40(2), 99-107.
  2. Alnahdi AH, Zeni JA, Snyder-Mackler L(2016). Quadriceps strength asymmetry predicts loading asymmetry during sit-to-stand task in patients with unilateral total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc, 24(8), 2587-2594.
  3. Bade MJ, Kohrt WM, Stevens-Lapsley JE(2010). Outcomes before and after total knee arthroplasty compared to healthy adults. J Orthop Sports Phys Ther, 40(9), 559-567.
  4. Barcellona MG, Morrissey MC, Milligan P, et al(2015). The effect of knee extensor open kinetic chain resistance training in the ACL-injured knee. Knee Surg Sports Traumatol Arthrosc, 23(11), 3168-3177.
  5. Bouchouras G, Patsika G, Hatzitaki V, et al(2015). Kinematics and knee muscle activation during sit-to-stand movement in women with knee osteoarthritis. Clin Biomech, 30(6), 599-607.
  6. Christanell F, Hoser C, Huber R, et al(2012). The influence of electromyographic biofeedback therapy on knee extension following anterior cruciate ligament reconstruction: a randomized controlled trial. Sports Med Arthrosc Rehabil Ther Technol, 4(1), 41.
  7. Christiansen CL, Bade MJ, Weitzenkamp DA, et al(2013). Factors predicting weight-bearing asymmetry 1 month after unilateral total knee arthroplasty: a cross-sectional study. Gait Posture, 37(3), 363-367.
  8. Horstmann H, Colcuc C, Lobenhoffer P, et al(2017). Evaluation of the acceptability of a sphygmomanometer device in knee extension training following surgical procedures of the knee. Int J Orthop Trauma Nurs, 25, 42-47.
  9. Levinger P, Menz HB, Morrow AD, et al(2012). Lower limb proprioception deficits persist following knee replacement surgery despite improvements in knee extension strength. Knee Surg Sports Traumatol Arthrosc, 20(6), 1097-1103.
  10. Lim SJ, Cho SH, Nam GS(2016). The effects of standing balance in anteroposterior and mediolateral directions on knee strengthening in post-total knee replacement. J Phys Ther Sci, 28(1), 261-263.
  11. Mcbeth JM, Earl-Boehm JE, Cobb SC, et al(2012). Hip muscle activity during 3 side-lying hip-strengthening exercises exercises in distance runners. J Athl Train, 47(1), 15-23.
  12. Medina-Mirapeix F, Vivo-Fernandez I, Lopez-Canizares J, et al(2018). Five times sit-to-stand test in subjects with total knee replacement: reliability and relationship with functional mobility tests. Gait Posture, 59, 258-260.
  13. Neumann DA(2010). Kinesiology of the musculoskeletal system: foundations for physical rehabilitation. 2nd ed, London, Elsevier Health Sciences, pp.560.
  14. Park DS, Lee DY, Choi SJ, et al(2013). Reliability and validity of the balancia using Wii balance board for assessment of balance with stroke patients. JKAIS, 14(6), 2767-2772.
  15. Pua YH, Liang Z, Ong PH, et al(2011). Associations of knee extensor strength and standing balance with physical function in knee osteoarthritis. Arthritis Care Res, 63(12), 1706-1714.
  16. Rossi MD, Everle T, Roche M, et al(2010). Closed-chain exercise after simultaneous bilateral knee replacement surgery: a case report. Physiother Theory Pract, 26(3), 204-214.
  17. Sharma L, Dunlop DD, Cahue S, et al(2003). Quadriceps strength and osteoarthritis progression in malaligned and lax knees. Ann Intern Med, 138(8), 613-619.
  18. Suh MJ, Kim BR, Kim SR, et al(2017). Effects of early combined eccentric-concentric versus concentric resistance training following total knee arthroplasty. Ann Rehabil Med, 41(5), 816-827.
  19. Yim SJ, Min KD, Lee YK, et al(2009). Efficacy of physiotherapist after total knee arthroplasty. Knee Surg Relat Res, 21(4), 258-264.