Table 1. Mechanical stimulations on growth plate chondrocytes.

↑: increase relative to control (or sham) group. ↓: decrease relative to control (or sham) group. —: negligible changes (or same) relative to control (or sham) group.

Year	Reference	Subject	Samples	Experiment type	Tools	Type of stress	Parameters	Brief results [relative to control (or sham) group]	Findings
1993	Alberty et al. [30]	New Zealand white rabbits 5–6 weeks	Left distal femoral physis	in-vivo	External fixator	Static compression	d = 0.5 mm/day (day ≤ 7 days) d = 3.5 mm (day ≥ 8 days) t = 3–21 days	The height of proliferative and hypertrophic zones: ↓ The height of resting zone: - The orientation of chondrocyte columns: distorted The number of proliferating chondrocytes:↓	1. Static compression suppresses growth plate proliferative activity and change growth plate morphology. 2. The role of static tension on bone growth is not clear.
						Static tension	d = 0.7 mm/day, t = 3–21 days	The Hight of proliferative and hypertrophic zones: ↑ The number of proliferating chondrocytes: -
2001	Robling et al. [34]	Male Sprague Dawley rat	Ulna	in-vivo	Compression device	Static compression	F = 17 N t = 10 min/day (days 1–5, 8–12)	Length of ulna: ↓ 4%	1. Peak load magnitude affects the growth suppression regardless of the type of compression and average load magnitude. 2. Thicker distal growth plate and accumulation of hypertrophic cell lacunae are related with growth suppression accumulation of hypertrophic cell lacunae are related with growth suppression.
							F = 8.5 N t = 10 min/day (days 1–5, 8–12)	Length of ulna: ↓ 2%
						Dynamic compression	F = 17 N f = 2 Hz t = 10 min/day (days 1–5, 8–12)	Length of ulna: ↓ 4%
2002	Wang and Mao [36]	New Zealand white rabbits 6 weeks	Cranial base growth plate	in-vivo	Mechanical testing equipment connected to maxillary central incisors	Static tension	F = 2 N t = 20 minutes/day (12 days)	Height of growth plate: ↑ 16% Height of proliferation zone: ↑ 117% The number of proliferative chondrocytes: -	1. Dynamic tension promotes chondral growth.
						Dynamic tension	F = 2 N f = 1 Hz t = 20 minutes/day (12 days)	Height of growth plate: ↑ 54% Height of proliferation zone: ↑ 193% The number of proliferative chondrocytes: ↑ 65%
2002	Stokes et al.[13]	Sprague Dawley rat	Caudal vertebra	in-vivo	External fixator	Static compression	F = 60% of body weight (~ 0.736 N) t = 4 weeks	Growth rate: ↓ 48% Height of hypertrophic zone: ↓ 13% Mean chondrocyte height: ↓ 15%	1. The effect of static compression is greater than static tension in bone growth. 2. The change in height of hypertrophic chondrocytes is related to growth rate.
						Static tension	F = 60% of body weight (~ 0.736 N) t = 4 weeks	Growth rate: ↑ 13% Height of hypertrophic zone:- Mean chondrocyte height: -
2006	Akyuz et al. [32]	Sprague Dawley rat	Caudal vertebra	in-vivo	External fixator	Static compression	F = 55% of body weight t = 3 weeks Asymmetric load	Average wedge deformity: 10.3 ± 3.7° (sham / control group: 1.1 ± 20°/ 0.0 ± 1.0°) Longitudinal growth: 0.46 ± 0.19 mm (concavity) / 0.83 ± 0.32 mm (convexity)	1. Dynamic compression has greater effects on the growth regulation.
						Dynamic compression	F = 55% of body weight f = 1.0 Hz t = 3 weeks Asymmetric load	Average wedge deformity: 15.2 ± 6.4° Longitudinal growth: 0.34 ± 0.23 mm (concavity) / 0.86 ± 0.23 mm (convexity)
2007	Stokes et al. [31]	Rat, 38 days Rabbit, 41 days Cattle, 48 days	Proximal tibia (Rat, cattle and rabbit) Caudal vertebra (Rat and cattle)	in-vivo	External fixator	Static compression	P = 0.1 MPa/0.2 MPa t = 7 days	Growth rate: ↓	1. The height of hypertrophic chondrocytes have a greater effect on growth rate than the number of proliferative chondrocytes.
						Static tension	P = 0.1 MPa t = 7 days	Growth rate: ↑
2008	Ueki et al. [25]	Male Wistar strain rat 4 weeks	Chondrocytes from rib growth plate	in-vitro	2D cell stretcher	Dynamic tension (2D)	P = 2 kPa f = 0.03 Hz t = 12 or 24 hours	Chondrocyte proliferation: - Collagen and proteoglycan syntheses: -	1. Chondrocyte metabolism improved due to increased frequency of tension.
							P = 2 kPa f = 0.5 Hz t = 12 or 24 hours	Chondrocyte proliferation: ↑ Collagen and proteoglycan syntheses: ↑
							P = 2 kPa f = 2.5 Hz t = 12 or 24 hours	Chondrocyte proliferation: ↑ Collagen and proteoglycan syntheses:↑
2009	Cancel et al. [16]	Male Sprague Dawley rat	7th Caudal vertebra (Cd7)	in-vivo	External fixator	Static compression	P = 0.2 MPa t = 2 weeks	Longitudinal growth rate: ↓ 28% Growth plate thickness: ↓ 25% Amount of MMP-3 expression: ↑ Type II and X collagen: ↓	1. The growth of caudal vertebrae was suppressed by 2-week static compression.
2011	Valteau et al. [17]	Male Sprague Dawley rat	7th Caudal vertebra (Cd7)	in-vivo	External fixator with pneumatic loading system	Static compression	P = 0.2 MPa t = 2 weeks	Growth rate: ↓ 21% Growth plate height: ↓ 20% Hypertrophic chondrocyte height: ↓ 25% The number of proliferative chondrocytes per column: ↓ 32%	1. Both static and dynamic compression modulate bone growth effectively. 2. Dynamic compression is less harmful on growth plate morphology than static compression.
						Dynamic compression	P = 0.2 ± 0.06 MPa f = 0.1 Hz t = 2 weeks	Growth rate: ↓ 21% Growth plate height: ↓ 11% Hypertrophic chondrocyte height: ↓ 15% The number of proliferative chondrocytes per column: ↓ 19%
2011	Sergerie et al. [23]	Swine 4 weeks	Distal ulnae (cylindrical explant, D = 6 mm, h = 3.04 ± 0.54 mm)	ex-vivo	Compression device with parallel plate	Static compression	ε = 10% t = 2 days	Chondrocyte column: structure is reserved Aggrecan, type II collagen, type X collagen, and MMP13:↓	1. Growth plate behaves differently depending on the type of compressive stress. 2. Dynamic compression increases the expression of extracellular matrix components.
						Dynamic compression	ε = 7 and 13% f = 0.1 Hz t = 2 days	Chondrocyte column: structure is distorted Aggrecan and type II collagen:↑
2014	Menard et al. [35]	Male Sprague Dawley rat 4 weeks	7th Caudal vertebra (Cd7)	in-vivo	External fixator with pneumatic loading system	Dynamic compression	P = 0.2 ± 0.06 MPa f = 1.0 Hz t = 15 days	Growth rate: ↓ 16% Growth plate height: ↓ 17% Hypertrophic chondrocyte height: ↓ 14% The number of proliferative chondrocytes per column: ↓15%	1. Increase in both magnitude and frequency of the stress destroys the integrity of growth plate.
							P = 0.2 ± 0.2 MPa f = 0.1 Hz t = 15 days	Growth rate: ↓ 17% Growth plate height: ↓ 8% Hypertrophic chondrocyte height: ↓ 11% The number of proliferative chondrocytes per column: ↓ 13%
							P = 0.2 ± 0.14 MPa f = 1.0 Hz t = 15 days	Tissues were damaged.
2015	Kaviani et al. [24]	Swine 4 weeks	Distal ulnae (cylindrical explant) D = 6 mm h = 9 mm	ex-vivo	Compression device with parallel plates	Static compression	P = 0.1 MPa / t = 12 hours	High stress:↓ viability of chondrocytes High frequency:↓ viability of chondrocytes Long loading time: ↓ viability of chondrocytes	1. Chondrocyte viability significantly decreases under the static compression with long loading time. 2. Proliferative and hypertrophic chondrocytes are susceptible to the stress.
							P = 0.2 MPa / t = 12 hours
							P = 0.1 MPa / t = 24 hours
						Dynamic compression	P = 0.1 ± 0.03 MPa /f = 0.1 Hz t = 12 hour
							P = 0.2 ± 0.06 MPa /f = 0.1 Hz t = 12 hour
							P = 1.0 ± 0.03 MPa /f = 0.1 Hz t = 24 hour
							P = 0.1 ± 0.03 MPa /f = 0.1 Hz t = 12 hour
							P = 0.1 ± 0.1 MPa /f = 0.1 Hz t = 12 hour
2017	Zimmermann et al. [20]	Male Sprague Dawley rat 27–30 days	Growth plate explants from tibia	ex-vivo	Compression device with parallel plate	Static compression	P = 0.2 MPa t = 2 hours	Hypertrophic chondrocytes compressed more in lateral direction than axial direction	1. Axial strains of hypertrophic chondrocytes are similar in all stress conditions. 2. Volumetric strains of cells decrease when the frequency becomes higher.
						Dynamic compression	P = 0.2 ± 0.06 MPa f = 0.1 Hz t = 2 hours	Hypertrophic chondrocytes maintained their shape under dynamic compression
							P = 0.2 ± 0.06 MPa f = 1.0 Hz t = 2 hours	Hypertrophic chondrocytes maintained their shape under dynamic compression
2017	Sun et al. [27]	Human (children with thumb duplication)	Chondrocytes from the growth plate of multi-fingered phalange	in-vitro	2D cell stretcher	Dynamic 2D stretching	ε= 0.2% f = 0.5 Hz t = 6 hours	Type 2 collagen, Type 10 collagen, and PTHrP: ↑	1. Proper amount of stretch promotes proliferation and differentiation of chondrocytes. 2. Excessive amount of stretch inhibits proliferation and differentiation of chondrocytes. 3. Excessive amount of stretch may induce cell death.
							ε= 0.4% f = 0.5 Hz t = 6 hours	Type 2 collagen, Type 10 collagen, and PTHrP: ↓