Isokinetic strength and functional capacity in soccer players 24 months after anterior cruciate ligament reconstruction

Parameter	Operated limb mean (SD)	Nonoperated limb mean (SD)	Mean difference (95% CI)	Effect size (Cohen’s d)	Significance (P-value)
Anterior reach	75.32 ± 6.77	76.20 ± 7.37	0.87 (−0.62 to 2.38)	0.25	0.238
Posteromedial reach	126.16 ± 10.23	125.17 ± 9.22	−0.98 (−2.35 to 0.37)	−0.31	0.148
Posterolateral reach	117.70 ± 7.57	116.43 ± 6.64	−1.27 (−3.48 to 0.94)	−0.24	0.247
Composite score	106.42 ± 5.81	106.03 ± 4.93	−0.39 (−1.56 to 0.078)	−0.14	0.497

Limb symmetry index percentages for isokinetic test, SHD, SH, and YBT

Parameter	90–110% (LSI)	>110% (LSI)	<90% (LSI)	Percentage of failure
Knee extension peak torque 60°/s (Nm)	11/24 (46%)	2/24 (8%)	11/24 (46%)	54%
Knee flexion peak torque 60°/s (Nm)	15/24 (62%)	3/24 (13%)	6/24 (25%)	26%
Knee extension peak torque 180°/s (Nm)	12/24 (50%)	2/24 (8%)	10/24 (42%)	50%
Knee flexion peak torque 180°/s (Nm)	9/24 (37%)	5/24 (21%)	10/24 (42%)	63%
Knee extension peak torque 300°/s (Nm)	14/24 (58%)	1/24 (4%)	9/24 (38%)	42%
Knee flexion peak torque 300°/s (Nm)	12/24 (50%)	3/24 (12%)	9/24 (38%)	50%
Single hop for distance (cm)	19/24 (79%)	1/24 (4%)	4/24 (17%)	17%
Side hop (number of hops)	10/24 (42%)	5/24 (21%)	9/24 (37%)	58%
Anterior reach (normalized to leg length)	23/24 (96%)	0/24 (0%)	1/24 (4%)	4%
Posteromedial reach (normalized to leg length)	24/24 (100%)	0/24 (0%)	0/24 (0%)	0%
Posterolateral reach (normalized to leg length)	23/24 (96%)	1/24 (4%)	0/24 (0%)	4%
Composite score (normalized to leg length)	24/24 (100%)	0/24 (0%)	0/24 (0%)	0%

Correlation between isokinetic peak torque of extensors and flexors and Y-balance reaches and composite score

	Knee extension peak torque 60°/s (Nm), r (95% CI)	p	Knee extension peak torque 180°/s (Nm), r (95% CI)	p
Anterior reach	−0.023 (−0.418 to 0.316)	0.915	0.049 (−0.476 to 0.496)	0.821
Posteromedial reach	0.581 (0.319 to 0.741)	0.003	0.531 (0.165 to 0.744)	0.008
Posterolateral reach	0.577 (0.206 to 0.790)	0.003	0.417 (0.011 to 0.699)	0.043
Composite score	0.582 (0.228 to 0.778)	0.003	0.505 (0.054 to 0.750)	0.012

Isokinetic values for knee extension and knee flexion peak torque between operated and nonoperated limb

Parameter	Operated limb, mean (SD)	Nonoperated limb, mean (SD)	Mean difference (95% CI)	Effect size (Cohen’s d)	Significance (P-value)
	Knee extension peak torque (Nm)
60°/s	179.04 ± 31.64	196.12 ± 35.35	17.08 (6.02 to 28.14)	0.65	0.004
180°/s	139.50 ± 19.99	151.29 ± 22.21	11.79 (2.80 to 20.77)	0.55	0.012
300°/s	107.04 ± 14.26	117.29 ± 14.26	10.25 (3.61 to 16.88)	0.65	0.004
	Knee flexion peak torque (Nm)
60°/s	112.79 ± 23.14	120.33 ± 21.26	7.54 (0.52 to 14.55)	0.45	0.036
180°/s	90.16 ± 15.09	94.87 ± 16.40	4.70 (−2.22 to 11.64)	0.29	0.173
300°/s	69.20 ± 12.90	73.95 ± 15.53	4.75 (−0.19 to 9.69)	0.41	0.059

Isokinetic values for H/Q conventional (Hamstring concentric peak torque/quadriceps concentric peak torque) and for H/Q Functional (Hamstring eccentric peak torque/quadriceps concentric peak torque) between operated and nonoperated limb

Parameter	Operated limb, mean (SD)	Nonoperated limb, mean (SD)	Mean difference (95% CI)	Effect size (Cohen’s d)	Significance (P-value)
	H/Q conventional ratio (Conv)
60°/s	63.37 ± 8.86	61.79 ± 9.12	−1.58 (−5.38 to 2.21)	−0.18	0.398
180°/s	65.29 ± 10.39	63.45 ± 11.22	−1.83 (−7.34 to 3.68)	−0.14	0.498
300°/s	65.29 ± 13.24	63.33 ± 12.28	−1.95 (−7.85 to 3.93)	−0.14	0.499
	H/Q functional ratio (Func)
60°/s	0.66 ± 0.12	0.61 ± 0.11	−0.05 (−0.13 to 0.01)	−0.35	0.120
180°/s	0.87 ± 0.21	0.86 ± 0.17	−0.006 (−0.11 to 0.10)	−0.03	0.905
300°/s	1.20 ± 0.26	1.03 ± 0.30	−0.16 (−0.34 to −0.02)	−0.39	0.088

Correlation between isokinetic peak torque of extensors and flexors and hop tests

Parameter	SHD (r)	p-value	95% CI	SH (r)	p-value	95% CI
Knee extension peak torque 60°/s	−0.073	0.736	[−0.454, 0.373]	0.480	0.018	[0.180, 0.723]
Knee extension peak torque 180°/s	−270	0.202	[−0.622, 0.186]	0.366	0.078	[−0.051, 0.715]
Knee extension peak torque 300°/s	−0.397	0.055	[−0.692, 0.006]	0.416	0.043	[0.048, 0.731]
Knee flexion peak torque 60°/s	−0.036	0.868	[−0.411, 0.434]	0.510	0.011	[0.098, 0.817]
Knee flexion peak torque 180°/s	−0.258	0.224	[−0.596, 0.159]	0.414	0.044	[−0.049, 0.761]
Knee flexion peak torque 300°/s	−0.318	0.129	[−0.598, 0.041]	0.401	0.052	[−0.032, 0.681]

Demographics characteristics of participants

Measure	Mean ± SD	Minimum	Maximum	Range
Age (years)	24.70 ± 4.35	18.00	33.00	15.00
Body mass (kg)	69.14 ± 8.18	57.00	85.00	28.00
Height (cm)	175.16 ± 6.98	160.00	185.00	25.00
BMI (kg/m²)	22.52 ± 2.67	20.06	31.60	11.54
Time from surgery (months)	23.79 ± 0.93	22.00	25.00	3.00
Rehabilitation time (months)	9.79 ± 3.24	6.00	18.00	12.00

Values for hop tests

Parameter	Operated limb (mean ± SD)	Nonoperated limb (mean ± SD)	Mean difference (95% CI)	Effect size (Cohen’s d)	Significance (p-value)
Single hop for distance (cm)	176.00 ± 34.10	181.07 ± 32.79	5.07 (−0.99 to 11.13)	0.35	p = 0.097
Side hop (number of hops)	38.75 ± 10.06	40.45 ± 9.10	1.70 (−1.026 to 4.44)	0.26	p = 0.209

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Articles in this issue

DOI: https://doi.org/10.2478/bhk-2026-0019 | Journal eISSN: 2080-2234

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Language: English

Page range: 202 - 216

Submitted on: Nov 7, 2025

Accepted on: May 4, 2026

Published on: Jun 2, 2026

Published by: University of Physical Education in Warsaw

In partnership with: Paradigm Publishing Services

Publication frequency: 1 issue per year

Keywords:

Anterior Cruciate Ligament Reconstruction,

Related subjects:

Basic medical science,

Basic medical science, other,

Clinical medicine,

Public health,

Sports and recreation,

Sports and recreation, other,

Physical education

© 2026 Konstantinos Chatzilamprinos, Eleni Semaltianou, Dimitrios Lytras, Vasileios Georgoulas, Ioannis Algiounidis, Evaggelos Sykaras, published by University of Physical Education in Warsaw
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Volume 18 (2026): Issue 1 (January 2026)