The Effects of Isolated versus Multiple Joint Exercises on the Knee, Hip and Ankle Musculature and Functional Tests.
Institution: Biodynamics and Human Performance Center. Armstrong Atlantic State University. Savannah, GA.
Authors: Jackson, A., Moreland, K., Oddi, C., Bringman, D. , Riemann, BL, Davies, GJ
Davies, GJ, Jackson, A., Moreland, K., Oddi, C., Bringman, D. , Riemann, BL. The Effects of Isolated versus Multiple Joint Exercises on the Knee, Hip and Ankle Musculature and Functional Tests. E-Poster. International Society of Arthroscopy Knee Surgery & Orthopaedic Sports Medicine Congress. Toronto, CAN., May 12-16, 2013
Purpose: Several studies have demonstrated the effectiveness of performing isolated or multiple joint exercises for strengthening the leg muscles and improving performance. However, neither of the exercises have consistently demonstrated superiority of either form of exercise. Therefore, the purpose was to investigate Closed Kinetic Chain (CKC) multi joint or Open Kinetic Chain (OKC) isolated joint exercises and effects on lower extremity (LE) muscular strength and functional performance tests (FPT). We hypothesized there would be a specificity training response; CKC group would improve in functional outcome measures; OKC group would improve in strength measures.
Subjects: 50 physically active subjects (17 male, 33 female), ages 18-40 years, volunteered and met inclusion criteria.
Methods: This was a prospective randomized pre-post test training study design. Outcome measures included: Isokinetic peak torque of knee extensors at 60, 180, 300 degrees/second; Hand Held Dynamometry (HHD) of knee flexors (KF), hip extensors (HE), and plantar flexors (PF); Vertical Jump (VJ); Double Leg Jump (DLJ); Single Leg Hop (SLH) of the dominant leg. Half of the subjects performed CKC squat exercises and the other half performed OKC exercises of the hip, knee and ankle for 3 sets of 10 repetitions twice a week starting with 70% 1 RM for 6 weeks with a 3% increase per week.
Results: Two factor mixed ANOVA (time and groups) revealed that both the CKC and OKC groups significantly improved on all outcome measures; however, there were no differences between the two groups. Main effect of time showed a significant increase from pre to post for both groups on all outcome measures: DLJ: [ p = 0.01], SLH: [p = 0.01], VJ: [ p = 0.01], Isokinetics at 60°/sec: [p = 0.002],180 °/sec: [p = 0.01], 300 °/sec: [p = 0.001], HEKE: [p = 0.01], HEKF: [p = 0.00], PF: [p = 0.00]
Conclusions: Either isolated or multiple joint exercises are effective in increasing both LE muscular strength and FPT.
Clinical Relevance: The results of this study have application to rehabilitation, strength and conditioning, and performance enhancement programs, where both modes of exercises are effective in improving LE muscular strength and FPT.