Table 3. Within-group pre–post changes in shoulder alignment and muscle mechanical properties (tone and stiffness) (paired t-tests)

	Group	Pre	Post	Difference value	t	Effect size(d)	p
RSP(cm)	EG	4.84±0.90	3.96±0.85	–0.88±0.40	–7.90	2.20	0.001*
	CG	5.39±1.26	4.48±1.14	–0.91±0.49	–6.72	1.86	0.001*
PML(cm)	EG	12.05±1.24	13.62±1.38	1.58±0.66	8.65	2.40	0.001*
	CG	11.64±1.34	13.54±1.03	1.90±0.84	8.19	2.27	0.001*
PM F(Hz)	EG	13.80±1.65	13.24±1.39	–0.55±0.70	–2.86	0.79	0.014*
	CG	13.72±1.96	12.92±1.48	–0.79±0.63	–4.57	1.27	0.001*
PM S(N/m)	EG	260.38±61.48	239.90±54.52	–20.49±32.11	–2.30	0.64	0.04*
	CG	247.87±53.09	233.00±42.46	–14.87±17.69	–3.03	0.84	0.01*
PD F(Hz)	EG	13.94±1.32	12.90±1.08	–1.03±0.47	–7.87	2.18	0.001*
	CG	14.67±1.22	14.40±1.38	–0.27±0.29	–3.35	0.93	0.006*
PD S(N/m)	EG	238.03±39.47	208.61±32.69	–29.41±19.06	–5.56	1.54	0.001*
	CG	254.61±41.21	244.78±35.39	–9.83±20.08	–1.77	0.49	0.103

RSP, rounded shoulder posture; PML, pectoralis minor length; PM, pectoralis major muscle; PD, posterior deltoid muscle; F, muscle tone; S, muscle stiffness; EG, posterior shoulder stretching with scapular posterior tilting exercise group; CG, pectoralis minor stretching with scapular posterior tilting exercise group; M±SD: mean ± standard deviation.
p<0.05.